2006 pearson education, inc. all rights reserved. 1 21 asp.net 2.0, web forms and web controls
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2006 Pearson Education, Inc. All rights reserved.
If any man will draw up his case, and put his name at the foot of the first page, I will give him an immediate reply. Where he compels me to turn over the sheet, he must wait my leisure.
— Lord Sandwich
Rule One: Our client is always rightRule Two: If you think our client is wrong, see Rule One.
— Anonymous
A fair question should be followed by a deed in silence.
— Dante Alighieri
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You will come here and get books that will open your eyes, and your ears, and your curiosity, and turn you inside out or outside in.
— Ralph Waldo Emerson
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OBJECTIVESIn this chapter you will learn: Web application development using ASP.NET. To create Web Forms. To create ASP.NET applications consisting of multiple
Web Forms. To maintain state information about a user with
session tracking and cookies. To use the Web Site Administration Tool to modify
Web application configuration settings. To control user access to Web applications using
forms authentication and ASP.NET login controls. To use databases in ASP.NET applications. To design a master page and content pages to create
a uniform look-and-feel for a Web site.
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2006 Pearson Education, Inc. All rights reserved.
21.1 Introduction
21.2 Simple HTTP Transactions
21.3 Multitier Application Architecture
21.4 Creating and Running a Simple Web-Form Example
21.4.1 Examining an ASPX File
21.4.2 Examining a Code-Behind File
21.4.3 Relationship Between an ASPX File and a Code-Behind File
21.4.4 How the Code in an ASP.NET Web Page Executes
21.4.5 Examining the XHTML Generated by an ASP.NET Application
21.4.6 Building an ASP.NET Web Application
21.5 Web Controls
21.5.1 Text and Graphics Controls
21.5.2 AdRotator Control
21.5.3 Validation Controls
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21.6 Session Tracking
21.6.1 Cookies
21.6.2 Session Tracking with HttpSessionState
21.7 Case Study: Connecting to a Database in ASP.NET
21.7.1 Building a Web Form That Displays Data from a Database
21.7.2 Modifying the Code-Behind File for the Guestbook Application
21.8 Case Study: Secure Books Database Application
21.8.1 Examining the Completed Secure Books Database Application
21.8.2 Creating the Secure Books Database Application
21.9 Wrap-Up
21.10 Web Resources
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21.1 Introduction
• ASP.NET 2.0 and Web Forms and Controls– Web application development with Microsoft’s ASP.NET 2.0
technology
– Web Form files have the filename extension .aspx and contain the Web page’s GUI
– Every ASPX file created in Visual Studio has a corresponding class written in a .NET language, such as C#
• Contains event handlers, initialization code, utility methods and other supporting code
• Called the code-behind file
• Provides the ASPX file’s programmatic implementation
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21.2 Simple HTTP Transactions
• Simple HTTP Transactions– HTTP specifies a set of methods and headers that allow clients and
servers to interact and exchange information – A Web page is nothing more than an XHTML document– A plain text file containing markup that describe to a Web browser
how to display and format the document’s information– Any XHTML document available for viewing over the Web has a
corresponding URL• An address indicating the location of an Internet resource
– When requesting ASP.NET Web applications, the Web server is usually Microsoft Internet Information Services (IIS)
– The information provided in the header specifies the Multipurpose Internet Mail Extensions (MIME) type of the content that the server is transmitting to the browser
• Internet standard that specifies data formats – Programs can interpret data correctly
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Fig. 21.1 | Client interacting with Web server. Step 1: The GET request.
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Fig. 21.2 | Client interacting with Web server. Step 2: The HTTP response.
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21.3 Multitier Application Architecture
• Web-based applications are multitier applications – Multitier applications divide functionality into separate tiers
• Bottom (information) tier – Maintains data pertaining to the application; typically stores data in a
RDBMS• Middle tier
– Implements business, controller and presentation logic to control interactions between the application’s clients and data
– Acts as an intermediary between data in the information tier and the application’s clients
• Top (client) tier– Application’s user interface: gathers input and displays output– Interacts with the middle tier to make requests and to retrieve data
from the information tier• Displays the data retrieved from the middle tier to the user• The client tier never directly interacts with the information tier
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21.4.1 Examining an ASPX File
• Examining an ASPX File – ASP.NET comments begin with <%-- and terminate with --%>
– Page directive • Specifies the language of the code-behind file
– AutoEventWireup attribute • Determines how Web Form events are handle
– Inherits attribute • Specifies the class in the code-behind file from which this ASP.NET class
inherits
– ASP.NET markup is not case-sensitive• Using a different case is not problematic
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21.4.1 Examining an ASPX File (Cont.)
– runat attribute • Indicates that when a client requests this ASPX file:
– Process the head element and its nested elements on the server
– Generate the corresponding XHTML• Sent to the client
– asp: tag prefix in a control declaration • Indicates that it is an ASP.NET Web control
– Each Web control maps to a corresponding XHTML element
• When processing a Web control, ASP.NET generates XHTML markup that will be sent to the client to represent that control in a Web browser
– span element • Contains text that is displayed in a Web page
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1 <%-- Fig. 21.4: WebTime.aspx --%>
2 <%-- A page that displays the current time in a Label. --%>
3 <%@ Page Language="C#" AutoEventWireup="true" CodeFile="WebTime.aspx.cs"
4 Inherits="WebTime" EnableSessionState="False" %>
5
6 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
7 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
8
9 <html xmlns="http://www.w3.org/1999/xhtml">
10 <head runat="server">
11 <title>A Simple Web Form Example</title>
12 </head>
13 <body>
14 <form id="form1" runat="server">
15 <div>
16 <h2>Current time on the Web server:</h2>
17 <p>
18 <asp:Label ID="timeLabel" runat="server" BackColor="Black"
19 Font-Size="XX-Large" ForeColor="Yellow"
20 EnableViewState="False"></asp:Label>
21 </p>
22 </div>
23 </form>
24 </body>
25 </html>
Outline
WebTime.aspx
ASP.NET comments
Page directive to specify information needed by
ASP.NET to process this file
Document type declaration
Mark up of a label web control
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Portability Tip 21.1
The same Web control can map to different XHTML elements, depending on the client browser and the Web control’s property settings.
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21.4.2 Examining a Code-Behind File
• Examining a Code-Behind File– System.Web.UI
• Contains classes and controls that assist in building Web-based applications
• Class Page – Provides event handlers and objects necessary for
creating Web-based applications– Method Page_Init
• Handles the Init event• Indicates that a page is ready to be initialized
• Class Control– The base class that provides common functionality for
all Web controls
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1 // Fig. 21.5: WebTime.aspx.cs
2 // Code-behind file for a page that displays the current time.
3 using System;
4 using System.Data;
5 using System.Configuration;
6 using System.Web;
7 using System.Web.Security;
8 using System.Web.UI;
9 using System.Web.UI.WebControls;
10 using System.Web.UI.WebControls.WebParts;
11 using System.Web.UI.HtmlControls;
12
13 public partial class WebTime : System.Web.UI.Page
14 {
15 // initializes the contents of the page
16 protected void Page_Init( object sender, EventArgs e )
17 {
18 // display the server's current time in timeLabel
19 timeLabel.Text = string.Format( "{0:D2}:{1:D2}:{2:D2}",
20 DateTime.Now.Hour, DateTime.Now.Minute, DateTime.Now.Second );
21 } // end method Page_Init
22 } // end class WebTime
Outline
WebTime.aspx.cs
(1 of 2)
Retrieve the current time and formats it as HH:MM:SS
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21.4.3 Relationship Between an ASPX File and a Code-Behind File
• ASP.NET creates two classes behind the scenes– A Partial class containing the remainder of the class
• Based on the markup in the ASPX file
– A class based on the ASPX file • Defines the page’s visual representation• The first time the Web page is requested, the class is
compiled, and an instance is created
• Web controls– System.Web.UI.WebControls– Derive from class WebControl
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Performance Tip 21.1
Once an instance of the Web page has been created, multiple clients can use it to access the page—no recompilation is necessary. The project will be recompiled only when you modify the application; changes are detected by the runtime environment, and the project is recompiled to reflect the altered content.
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21.4.4 How the Code in an ASP.NET Web Page Executes
• How the Code in an ASP.NET Web Page Executes – Init event
• Occurs when an instance of a page is created– Load event occurs and the Page_Load event handler executes
• Inherited from class Page – Typically overridden to perform any processing that is necessary to
restore data from previous requests
– The page processes any events raised by the page’s controls after Page_Load finishes executing
– Unload event occurs when a Web Form object is ready for garbage collection
• Event handler Page_Unload – Inherited from class Page – Contains any code that releases resources
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21.4.5 Examining the XHTML Generated by an ASP.NET Application• XHTML Generated by an ASP.NET Application
– XHTML forms can contain visual and nonvisual components
– Attribute method
• Specifies the method by which the Web browser submits the form to the server
– Attribute action
• Identifies the name and location of the resource that will be requested when this form is submitted
– The runat attribute is removed when the form is processed on the server
• The method and action attributes are added
• The resulting XHTML form is sent to the client browser
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1 <!-- Fig. 21.6: WebTime.html -->
2 <!-- The XHTML generated when WebTime.aspx is loaded. -->
3 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
4 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
5
6 <html xmlns="http://www.w3.org/1999/xhtml">
7 <head>
8 <title>A Simple Web Form Example</title>
9 </head>
10 <body>
11 <form method="post" action="WebTime.aspx" id="form1">
12 <div>
13 <input type="hidden" name="__VIEWSTATE"
14 id="__VIEWSTATE" value=
15 "/wEPDwUJODExMDE5NzY5ZGQ4n4mht8D7Eqxn73tM5LDnstPlCg==" />
16 </div>
17
18 <div>
19 <h2>Current time on the Web server:</h2>
20 <p>
21 <span id="timeLabel" style="color:Yellow;
22 background-color:Black;font-size:XX-Large;">
23 17:13:52
24 </span>
25 </p>
26 </div>
27 </form>
28 </body>
29 </html>
Outline
WebTime.html
Declaration for a non-visual component: hidden input
Represents the text in the label
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21.4.6 Building an ASP.NET Web Application
• Step 1: Creating the Web Application Project (Fig. 21.7)
– http://localhost (IIS’s root directory) corresponds to C:\InetPub\wwwroot
• Step 2: Examining the Solution Explorer of the Newly Created Project (Fig. 21.8)
• Step 3: Examining the Toolbox in Visual Web Developer (Fig. 21.9)
• Step 4: Examining the Web Forms Designer (Fig. 21.10-11)
• Step 5: Examining the Code-Behind File in the IDE (Fig. 21.12)
• Step 6: Renaming the ASPX File
• Step 7: Renaming the Class in the Code-Behind File and Updating the ASPX File
• Step 8: Changing the Title of the Page
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21.4.6 Building an ASP.NET Web Application (Cont.)
• Step 9: Designing the Page (Fig. 21.13)
– Relative positioning
• Positions of controls and other elements are relative to the Web Form’s upper-left corner
– Absolute positioning
• Controls are located exactly where they are dropped on the Web Form
– Visual Web Developer is a WYSIWYG editor
• “What You See Is What You Get”
• Step 10: Adding Page Logic
– Web.config stores configuration settings for an ASP.NET Web application
• Step 11: Running the Program
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Fig. 21.7 | Creating an ASP.NET Web Site in Visual Web Developer.
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Fig. 21.8 | Solution Explorer window for project WebTime.
Code-behind file
Properties
Refresh
Nest Related Files
View Code
View Designer Copy Web Site
ASP.NET Configuration
ASPX file
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Fig. 21.9 | Toolbox in Visual Web Developer.
(a) (b)
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Fig. 21.10 | Source mode of the Web Forms Designer.
Design mode button
Source mode button
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Fig. 21.11 | Design mode of the Web Forms Designer.
Cursor
Cursor’s current location
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Fig. 21.12 | Code-behind file for Default.aspx generated by Visual Web Developer.
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Portability Tip 21.2
Absolute positioning is discouraged, because pages designed in this manner may not render correctly on computers with different screen resolutions and font sizes. This could cause absolutely positioned elements to overlap each other or display off-screen, requiring the client to scroll to see the full page content.
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Fig. 21.13 | WebTime.aspx after inserting text and a new paragraph.
Cursor position after inserting text and a new paragraph by pressing Enter
Block Format drop-down list
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Fig. 21.14 | WebTime.aspx after adding a Label and setting its properties.
Label
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Fig. 21.15 | Commonly used Web controls.
Web Control Description
Label Displays text that the user cannot edit.
TextBox Gathers user input and displays text.
Button Triggers an event when clicked.
HyperLink Displays a hyperlink.
DropDownList Displays a drop-down list of choices from which a user can select an item.
RadioButtonList Groups radio buttons.
Image Displays images (e.g., GIF and JPG).
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21.5.1 Text and Graphics Controls• Examining Web Controls on a Sample Registration Form
– Image control • Inserts an image into a Web page
– ImageUrl property specifies the file location of the image to display– TextBox control
• Allows the you to obtain text from the user and display text to the user– DropDownList control
• Provides a list of options to the user• Each item in the drop-down list is defined by a ListItem element
– HyperLink control • Adds a hyperlink to a Web page
– NavigateUrl property specifies the resource that is requested– RadioButtonList control
• Provides a series of radio buttons for the user– Button control
• Represents a button that triggers an action when clicked
– Visual Web Developer displays smart tag menus for many ASP.NET controls to facilitate performing common tasks
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1 <%-- Fig. 21.16: WebControls.aspx --%>
2 <%-- Registration form that demonstrates Web controls. --%>
3 <%@ Page Language="C#" AutoEventWireup="true"
4 CodeFile="WebControls.aspx.cs" Inherits="WebControls"
5 EnableSessionState="False" %>
6
7 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
8 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
9
10 <html xmlns="http://www.w3.org/1999/xhtml">
11 <head runat="server">
12 <title>Web Controls Demonstration</title>
13 </head>
14 <body>
15 <form id="form1" runat="server">
16 <div>
17 <h3>This is a sample registration form.</h3>
18 <p><em>Please fill in all fields and click Register.</em></p>
19 <p>
20 <asp:Image ID="UserInformationImage" runat="server"
21 ImageUrl="~/Images/user.png" EnableViewState="False" />
22
23 <span style="color: teal">
24 Please fill out the fields below.</span>
25 </p>
Outline
WebControls.aspx
(1 of 6)
Define an Image control
Set the color of a specific piece of text
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26 <table>
27 <tr>
28 <td style="width: 230px; height: 21px" valign="top">
29 <asp:Image ID="FirstNameImage" runat="server"
30 ImageUrl="~/Images/fname.png"
31 EnableViewState="False" />
32 <asp:TextBox ID="FirstNameTextBox" runat="server"
33 EnableViewState="False"></asp:TextBox>
34 </td>
35 <td style="width: 231px; height: 21px" valign="top">
36 <asp:Image ID="LastNameImage" runat="server"
37 ImageUrl="~/Images/lname.png"
38 EnableViewState="False" />
39 <asp:TextBox ID="LastNameTextBox" runat="server"
40 EnableViewState="False"></asp:TextBox>
41 </td>
42 </tr>
43 <tr>
44 <td style="width: 230px" valign="top">
45 <asp:Image ID="EmailImage" runat="server"
46 ImageUrl="~/Images/email.png"
47 EnableViewState="False" />
48 <asp:TextBox ID="EmailTextBox" runat="server"
49 EnableViewState="False"></asp:TextBox>
50 </td>
Outline
WebControls.aspx
(2 of 6)
Define a TextBox control used to collect the user’s first name
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51 <td style="width: 231px" valign="top">
52 <asp:Image ID="PhoneImage" runat="server"
53 ImageUrl="~/Images/phone.png"
54 EnableViewState="False" />
55 <asp:TextBox ID="PhoneTextBox" runat="server"
56 EnableViewState="False"></asp:TextBox><br />
57 Must be in the form (555) 555-5555.
58 </td>
59 </tr>
60 </table>
61 <p>
62 <asp:Image ID="PublicationsImage" runat="server"
63 ImageUrl="~/Images/publications.png"
64 EnableViewState="False" />
65
66 <span style="color: teal">
67 Which book would you like information about?</span>
68 </p>
69 <p>
70 <asp:DropDownList ID="BooksDropDownList" runat="server"
71 EnableViewState="False">
72 <asp:ListItem>Visual Basic 2005 How to Program 3e
73 </asp:ListItem>
74 <asp:ListItem>Visual C# 2005 How to Program 2e
75 </asp:ListItem>
76 <asp:ListItem>Java How to Program 6e</asp:ListItem>
77 <asp:ListItem>C++ How to Program 5e</asp:ListItem>
78 <asp:ListItem>XML How to Program 1e</asp:ListItem>
79 </asp:DropDownList>
80 </p>
Outline
WebControls.aspx
(3 of 6)
Defines a DropDownList
Each item in the drop-down list is defined by a ListItem element
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81 <p>
82 <asp:HyperLink ID="BooksHyperLink" runat="server"
83 NavigateUrl="http://www.deitel.com" Target="_blank"
84 EnableViewState="False">
85 Click here to view more information about our books
86 </asp:HyperLink>
87 </p>
88 <p>
89 <asp:Image ID="OSImage" runat="server"
90 ImageUrl="~/Images/os.png" EnableViewState="False" />
91
92 <span style="color: teal">
93 Which operating system are you using?</span>
94 </p>
95 <p>
96 <asp:RadioButtonList ID="OperatingSystemRadioButtonList"
97 runat="server" EnableViewState="False">
98 <asp:ListItem>Windows XP</asp:ListItem>
99 <asp:ListItem>Windows 2000</asp:ListItem>
100 <asp:ListItem>Windows NT</asp:ListItem>
101 <asp:ListItem>Linux</asp:ListItem>
102 <asp:ListItem>Other</asp:ListItem>
103 </asp:RadioButtonList>
104 </p>
Outline
WebControls.aspx
(4 of 6)Adds a hyperlink to the web page
Defines a RadioButtonList
control
Each item in the drop-down list is defined by a ListItem element
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105 <p>
106 <asp:Button ID="RegisterButton" runat="server"
107 Text="Register" EnableViewState="False" />
108 </p>
109 </div>
110 </form>
111 </body>
112 </html>
Outline
WebControls.aspx
(5 of 6)Defines a Button web control
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Outline
WebControls.aspx
(6 of 6)Image control
TextBox control
DropDownList control
HyperLink control
RadioButtonList control
Button control
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Fig. 21.17 | DropDownList Tasks smart tag menu.
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21.5.2 AdRotator Control
•AdRotator control – Randomly selects an image to display
– Generates a hyperlink to the Web page associated with that image
– Browsers that do not support images display alternate text that is specified in the XML document
– The browser loads the Web page associated with that image when a user clicks the image or substituted text
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21.5.2 AdRotator Control (Cont.)• AdRotator control
– Accesses an XML file to determine what advertisement image, hyperlink URL and alternate text to display and include in the page
• Create an XmlDataSource control to connect to the XML file – ImageUrl Element
• Specifies the path (location) of the advertisement’s image
– NavigateUrl Element • Specifies the URL for the Web page that loads when a user clicks the
advertisement– The URL cannot contain any whitespace
– AlternateText Element • Contains text that displays in place of the image when the browser cannot
locate or render the image– Also a tooltip
– Impressions Element • Specifies how often a particular image appears, relative to the other images
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1 <%-- Fig. 21.18: FlagRotator.aspx --%>
2 <%-- A Web Form that displays flags using an AdRotator control. --%>
3 <%@ Page Language="C#" AutoEventWireup="true"
4 CodeFile="FlagRotator.aspx.cs" Inherits="FlagRotator"
5 EnableSessionState="False" %>
6
7 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
8 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
9
10 <html xmlns="http://www.w3.org/1999/xhtml" >
11 <head runat="server">
12 <title>Flag Rotator</title>
13 </head>
14 <body background="Images/background.png">
15 <form id="form1" runat="server">
16 <div>
17 <h3>AdRotator Example</h3>
18 <p>
19 <asp:AdRotator ID="countryRotator" runat="server"
20 DataSourceID="adXmlDataSource"
21 EnableViewState="False" />
22 <asp:XmlDataSource ID="adXmlDataSource" runat="server"
23 DataFile="~/App_Data/AdRotatorInformation.xml">
24 </asp:XmlDataSource>
25 </p>
26 </div>
27 </form>
28 </body>
29 </html>
Outline
FlagRotator.aspx
(1 of 2)
Defines an AdRotator
control
Defines an XmlDataSource control, which supplies the data
to the AdRotator control
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Outline
FlagRotator.aspx
(2 of 2)
(a)
AdRotator image
AlternativeText displayed in a tooltip
(b)
(c)
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1 <?xml version="1.0" encoding="utf-8"?>
2 <!-- Fig. 21.19: AdRotatorInformation.xml -->
3 <!-- XML file containing advertisement information. -->
4 <Advertisements>
5 <Ad>
6 <ImageUrl>Images/france.png</ImageUrl>
7 <NavigateUrl>
8 http://www.odci.gov/cia/publications/factbook/geos/fr.html
9 </NavigateUrl>
10 <AlternateText>France Information</AlternateText>
11 <Impressions>1</Impressions>
12 </Ad>
13
14 <Ad>
15 <ImageUrl>Images/germany.png</ImageUrl>
16 <NavigateUrl>
17 http://www.odci.gov/cia/publications/factbook/geos/gm.html
18 </NavigateUrl>
19 <AlternateText>Germany Information</AlternateText>
20 <Impressions>1</Impressions>
21 </Ad>
22
23 <Ad>
24 <ImageUrl>Images/italy.png</ImageUrl>
25 <NavigateUrl>
26 http://www.odci.gov/cia/publications/factbook/geos/it.html
27 </NavigateUrl>
28 <AlternateText>Italy Information</AlternateText>
29 <Impressions>1</Impressions>
30 </Ad>
Outline
AdRotatorInformation.xml
(1 of 4)Each Ad element represents an advertisement that will
be displayed by the AdRotator control
Specifies the path of the advertisement’s image
Specifies the URL for the Web page that loads when user
clicks on the advertisement
Text that displays in place of the image when the browser cannot render the image
Specifies how often a particular image appears
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31
32 <Ad>
33 <ImageUrl>Images/spain.png</ImageUrl>
34 <NavigateUrl>
35 http://www.odci.gov/cia/publications/factbook/geos/sp.html
36 </NavigateUrl>
37 <AlternateText>Spain Information</AlternateText>
38 <Impressions>1</Impressions>
39 </Ad>
40
41 <Ad>
42 <ImageUrl>Images/latvia.png</ImageUrl>
43 <NavigateUrl>
44 http://www.odci.gov/cia/publications/factbook/geos/lg.html
45 </NavigateUrl>
46 <AlternateText>Latvia Information</AlternateText>
47 <Impressions>1</Impressions>
48 </Ad>
49
50 <Ad>
51 <ImageUrl>Images/peru.png</ImageUrl>
52 <NavigateUrl>
53 http://www.odci.gov/cia/publications/factbook/geos/pe.html
54 </NavigateUrl>
55 <AlternateText>Peru Information</AlternateText>
56 <Impressions>1</Impressions>
57 </Ad>
Outline
AdRotatorInformation.xml
(2 of 4)
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58
59 <Ad>
60 <ImageUrl>Images/senegal.png</ImageUrl>
61 <NavigateUrl>
62 http://www.odci.gov/cia/publications/factbook/geos/sg.html
63 </NavigateUrl>
64 <AlternateText>Senegal Information</AlternateText>
65 <Impressions>1</Impressions>
66 </Ad>
67
68 <Ad>
69 <ImageUrl>Images/sweden.png</ImageUrl>
70 <NavigateUrl>
71 http://www.odci.gov/cia/publications/factbook/geos/sw.html
72 </NavigateUrl>
73 <AlternateText>Sweden Information</AlternateText>
74 <Impressions>1</Impressions>
75 </Ad>
76
77 <Ad>
78 <ImageUrl>Images/thailand.png</ImageUrl>
79 <NavigateUrl>
80 http://www.odci.gov/cia/publications/factbook/geos/th.html
81 </NavigateUrl>
82 <AlternateText>Thailand Information</AlternateText>
83 <Impressions>1</Impressions>
84 </Ad>
Outline
AdRotatorInformation.xml
(3 of 4)
52
2006 Pearson Education, Inc. All rights reserved.
85
86 <Ad>
87 <ImageUrl>Images/unitedstates.png</ImageUrl>
88 <NavigateUrl>
89 http://www.odci.gov/cia/publications/factbook/geos/us.html
90 </NavigateUrl>
91 <AlternateText>United States Information</AlternateText>
92 <Impressions>1</Impressions>
93 </Ad>
94 </Advertisements>
Outline
AdRotatorInformation.xml
(4 of 4)
53
2006 Pearson Education, Inc. All rights reserved.
21.5.3 Validation Controls
•Validation Control – Determines whether the data in another Web control is in
the proper format
– Provide a mechanism for validating user input on the client
– The validator is converted into ECMAScript when the XHTML for the page is created
• ECMAScript is a scripting language that enhances the functionality and appearance of Web pages
– For security reasons, validation is always performed on the server
54
2006 Pearson Education, Inc. All rights reserved.
21.5.3 Validation Controls (Cont.)– ControlToValidate property
• Indicates Validator verifies a control’s contents
– ErrorMessage Property• Text displayed if the validation fails
– Display property• Determines if the validator is displayed only when validation fails
– RegularExpressionValidator• Matches a Web control’s content against a regular expression
– That expression is assigned to ValidationExpression property
– IsPostBack property • Determines whether the page is being loaded due to a postback
– The current page reloads when the user submits the form
• EnableViewState attribute– Determines whether a Web control’s state persists when a postback
occurs
55
2006 Pearson Education, Inc. All rights reserved.
1 <%-- Fig. 21.20: Validation.aspx --%>
2 <%-- Form that demonstrates using validators to validate user input. --%>
3 <%@ Page Language="C#" AutoEventWireup="true"
4 CodeFile="Validation.aspx.cs" Inherits="Validation" %>
5
6 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
7 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
8
9 <html xmlns="http://www.w3.org/1999/xhtml" >
10 <head runat="server">
11 <title>Demonstrating Validation Controls</title>
12 </head>
13 <body>
14 <form id="form1" runat="server">
15 <div>
16 Please fill out the following form.<br />
17 <em>All fields are required and must
18 contain valid information.</em><br />
19 <br />
Outline
Validation.aspx
(1 of 6)
56
2006 Pearson Education, Inc. All rights reserved.
20 <table>
21 <tr>
22 <td style="width: 100px" valign="top">Name:</td>
23 <td style="width: 450px" valign="top">
24 <asp:TextBox ID="nameTextBox" runat="server">
25 </asp:TextBox><br />
26 <asp:RequiredFieldValidator ID="nameInputValidator"
27 runat="server" ControlToValidate="nameTextBox"
28 ErrorMessage="Please enter your name."
29 Display="Dynamic"></asp:RequiredFieldValidator>
30 </td>
31 </tr>
32 <tr>
33 <td style="width: 100px" valign="top">
34 E-mail address:</td>
35 <td style="width: 450px" valign="top">
36 <asp:TextBox ID="emailTextBox" runat="server">
37 </asp:TextBox>
38 e.g., user@domain.com<br />
39 <asp:RequiredFieldValidator ID="emailInputValidator"
40 runat="server" ControlToValidate="emailTextBox"
41 ErrorMessage="Please enter your e-mail address."
42 Display="Dynamic"></asp:RequiredFieldValidator>
Outline
Validation.aspx
(2 of 6)
Defines a RequiredFieldValidator which confirms the TextBox is
not empty
57
2006 Pearson Education, Inc. All rights reserved.
43 <asp:RegularExpressionValidator
44 ID="emailFormatValidator" runat="server"
45 ControlToValidate="emailTextBox"
46 ErrorMessage="Please enter an e-mail address in a
47 valid format." Display="Dynamic"
48 ValidationExpression=
49 "\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*">
50 </asp:RegularExpressionValidator>
51 </td>
52 </tr>
53 <tr>
54 <td style="width: 100px" valign="top">Phone number:</td>
55 <td style="width: 450px" valign="top">
56 <asp:TextBox ID="phoneTextBox" runat="server">
57 </asp:TextBox>
58 e.g., (555) 555-1234<br />
59 <asp:RequiredFieldValidator ID="phoneInputValidator"
60 runat="server" ControlToValidate="phoneTextBox"
61 ErrorMessage="Please enter your phone number."
62 Display="Dynamic"></asp:RequiredFieldValidator>
Outline
Validation.aspx
(3 of 6)
Defines a RegularExpressionValidator
control to determine whether data is entered in a valid format
Defines a RequiredFieldValidator which confirms the TextBox is
not empty
58
2006 Pearson Education, Inc. All rights reserved.
63 <asp:RegularExpressionValidator
64 ID="phoneFormatValidator" runat="server"
65 ControlToValidate="phoneTextBox"
66 ErrorMessage="Please enter a phone number in a
67 valid format." Display="Dynamic"
68 ValidationExpression=
69 "((\(\d{3}\) ?)|(\d{3}-))?\d{3}-\d{4}">
70 </asp:RegularExpressionValidator>
71 </td>
72 </tr>
73 </table>
74 <br />
75 <asp:Button ID="submitButton" runat="server" Text="Submit" />
76 <br /><br />
77 <asp:Label ID="outputLabel" runat="server"
78 Text="Thank you for your submission."
79 Visible="False"></asp:Label>
80 </div>
81 </form>
82 </body>
83 </html>
Outline
Validation.aspx
(4 of 6)
Defines a RegularExpressionValidator
control to determine whether data is entered in a valid format
61
2006 Pearson Education, Inc. All rights reserved.
1 // Fig. 21.21: Validation.aspx.cs
2 // Code-behind file for the form demonstrating validation controls.
3 using System;
4 using System.Data;
5 using System.Configuration;
6 using System.Web;
7 using System.Web.Security;
8 using System.Web.UI;
9 using System.Web.UI.WebControls;
10 using System.Web.UI.WebControls.WebParts;
11 using System.Web.UI.HtmlControls;
12
13 public partial class Validation : System.Web.UI.Page
14 {
15 // Page_Load event handler executes when the page is loaded
16 protected void Page_Load( object sender, EventArgs e )
17 {
18 // if this is not the first time the page is loading
19 // (i.e., the user has already submitted form data)
20 if ( IsPostBack )
21 {
22 // retrieve the values submitted by the user
23 string name = Request.Form[ "nameTextBox" ];
24 string email = Request.Form[ "emailTextBox" ];
25 string phone = Request.Form[ "phoneTextBox" ];
Outline
Validation.aspx.cs
(1 of 2)
Determines whether the page is being loaded due to a postback
Uses the Request object to retrieve the values of the TextBoxes
62
2006 Pearson Education, Inc. All rights reserved.
26
27 // create a table indicating the submitted values
28 outputLabel.Text +=
29 "<br />We received the following information:" +
30 "<table style=\"background-color: yellow\">" +
31 "<tr><td>Name: </td><td>" + name + "</td></tr>" +
32 "<tr><td>E-mail address: </td><td>" + email + "</td></tr>" +
33 "<tr><td>Phone number: </td><td>" + phone + "</td></tr>" +
34 "<table>";
35
36 outputLabel.Visible = true; // display the output message
37 } // end if
38 } // end method Page_Load
39 } // end class Validation
Outline
Validation.aspx.cs
(2 of 2)
63
2006 Pearson Education, Inc. All rights reserved.
Performance Tip 21.2
Setting EnableViewState to False reduces the amount of data passed to the Web server with each request.
64
2006 Pearson Education, Inc. All rights reserved.
1 <!-- Fig. 21.22: Validation.html -->
2 <!-- The XHTML and ECMAScript generated for Validation.aspx -->
3 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
4 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
5
6 <html xmlns="http://www.w3.org/1999/xhtml" >
7 <head>
8 <title>Demonstrating Validation Controls</title>
9 </head>
10 <body>
11 <form method="post" action="Validation.aspx"
12 onsubmit="javascript:return WebForm_OnSubmit();" id="form1">
13 <div>
14 <input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE"
15 value="/wEPDwUJODc5MTExMzA4D2QWAgIDD2QWAgITDw8WBB4EVGV4dAWQ
16 AlRoYW5rIHlvdSBmb3IgeW91ciBzdWJtaXNzaW9uLjxiciAvPldlIHJlY2V
17 pdmVkIHRoZSBmb2xsb3dpbmcgaW5mb3JtYXRpb246PHRhYmxlIHN0eWxlPS
18 JiYWNrZ3JvdW5kLWNvbG9yOiB5ZWxsb3ciPjx0cj48dGQ+TmFtZTogPC90Z
19 D48dGQ+Qm9iPC90ZD48L3RyPjx0cj48dGQ+RS1tYWlsIGFkZHJlc3M6IDwv
20 dGQ+PHRkPmJ3aGl0ZUBlbWFpbC5jb208L3RkPjwvdHI+PHRyPjx0ZD5QaG9
21 uZSBudW1iZXI6IDwvdGQ+PHRkPig1NTUpIDU1NS0xMjM0PC90ZD48L3RyPj
22 wvdGFibGU+HgdWaXNpYmxlZ2RkZHiyTaX3DhELahxLUxCHnaZuvuMd" />
23 </div>
24
25 <script src="/Validation/WebResource.axd?d=kpdxzzpR0gHb8glw78d_
26 hfkpmf1QLBVBMoL34vcFGS41&t=632494248729409088"
27 type="text/javascript"></script>
Outline
Validation.html
(1 of 9)A hidden input in the XHTML
document contains the data of the controls on this page
ECMAScript that provides the implementation for the
validation controls and for performing the postback
65
2006 Pearson Education, Inc. All rights reserved.
28
29 <script type="text/javascript">
30 <!--
31 function WebForm_OnSubmit() {
32 if (ValidatorOnSubmit() == false) return false;
33 return true;
34 }
35 // -->
36 </script>
37
38 <div>
39 Please fill out the following form.<br />
40 <em>All fields are required and must
41 contain valid information.</em><br />
42 <br />
43 <table>
44 <tr>
45 <td style="width: 100px" valign="top">Name:</td>
46 <td style="width: 450px" valign="top">
47 <input name="nameTextBox" type="text"
48 id="nameTextBox" /><br />
49 <span id="nameInputValidator" style="color:Red;
50 display:none;">Please enter your name.</span>
51 </td>
52 </tr>
Outline
Validation.html
(2 of 9)
66
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53 <tr>
54 <td style="width: 100px" valign="top">
55 E-mail address:</td>
56 <td style="width: 450px" valign="top">
57 <input name="emailTextBox" type="text"
58 id="emailTextBox" />
59 e.g., user@domain.com<br />
60 <span id="emailInputValidator" style="color:Red;
61 display:none;">Please enter your e-mail address.
62 </span>
63 <span id="emailFormatValidator" style="color:Red;
64 display:none;">Please enter an e-mail address in a
65 valid format.</span>
66 </td>
67 </tr>
68 <tr>
69 <td style="width: 100px" valign="top">Phone number:</td>
70 <td style="width: 450px" valign="top">
71 <input name="phoneTextBox" type="text"
72 id="phoneTextBox" />
73 e.g., (555) 555-1234<br />
74 <span id="phoneInputValidator" style="color:Red;
75 display:none;">Please enter your phone number.
76 </span>
77 <span id="phoneFormatValidator" style="color:Red;
78 display:none;">Please enter a phone number in a
79 valid format.</span>
80 </td>
81 </tr>
82 </table>
Outline
Validation.html
(3 of 9)
67
2006 Pearson Education, Inc. All rights reserved.
83 <br />
84 <input type="submit" name="submitButton" value="Submit"
85 onclick="javascript:WebForm_DoPostBackWithOptions(
86 new WebForm_PostBackOptions("submitButton",
87 "", true, "", "",
88 false, false))" id="submitButton" />
89 <br /><br />
90 <span id="outputLabel">Thank you for your submission.<br />
91 We received the following information:
92 <table style="background-color: yellow">
93 <tr><td>Name: </td><td>Bob</td></tr>
94 <tr><td>E-mail address: </td><td>bwhite@email.com</td></tr>
95 <tr><td>Phone number: </td><td>(555) 555-1234</td></tr>
96 </table>
97 </span>
98 </div>
99
100 <script type="text/javascript">
101 <!--
102 var Page_Validators = new Array(
103 document.getElementById("nameInputValidator"),
104 document.getElementById("emailInputValidator"),
105 document.getElementById("emailFormatValidator"),
106 document.getElementById("phoneInputValidator"),
107 document.getElementById("phoneFormatValidator"));
108 // -->
109 </script>
Outline
Validation.html
(4 of 9)
ECMAScript that provides the implementation for the
validation controls and for performing the postback
68
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110
111 <script type="text/javascript">
112 <!--
113 var nameInputValidator =
114 document.all ? document.all["nameInputValidator"] :
115 document.getElementById("nameInputValidator");
116 nameInputValidator.controltovalidate = "nameTextBox";
117 nameInputValidator.errormessage = "Please enter your name.";
118 nameInputValidator.display = "Dynamic";
119 nameInputValidator.evaluationfunction =
120 "RequiredFieldValidatorEvaluateIsValid";
121 nameInputValidator.initialvalue = "";
122
123 var emailInputValidator =
124 document.all ? document.all["emailInputValidator"] :
125 document.getElementById("emailInputValidator");
126 emailInputValidator.controltovalidate = "emailTextBox";
127 emailInputValidator.errormessage =
128 "Please enter your e-mail address.";
129 emailInputValidator.display = "Dynamic";
130 emailInputValidator.evaluationfunction =
131 "RequiredFieldValidatorEvaluateIsValid";
132 emailInputValidator.initialvalue = "";
133
134 var emailFormatValidator =
135 document.all ? document.all["emailFormatValidator"] :
136 document.getElementById("emailFormatValidator");
137 emailFormatValidator.controltovalidate = "emailTextBox";
138 emailFormatValidator.errormessage =
Outline
Validation.html
(5 of 9)
ECMAScript that provides the implementation for the
validation controls and for performing the postback
69
2006 Pearson Education, Inc. All rights reserved.
139 "Please enter an e-mail address in a \r\n " +
140 " valid format.";
141 emailFormatValidator.display = "Dynamic";
142 emailFormatValidator.evaluationfunction =
143 "RegularExpressionValidatorEvaluateIsValid";
144 emailFormatValidator.validationexpression =
145 "\\w+([-+.\']\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*";
146
147 var phoneInputValidator =
148 document.all ? document.all["phoneInputValidator"] :
149 document.getElementById("phoneInputValidator");
150 phoneInputValidator.controltovalidate = "phoneTextBox";
151 phoneInputValidator.errormessage =
152 "Please enter your phone number.";
153 phoneInputValidator.display = "Dynamic";
154 phoneInputValidator.evaluationfunction =
155 "RequiredFieldValidatorEvaluateIsValid";
156 phoneInputValidator.initialvalue = "";
Outline
Validation.html
(6 of 9)
ECMAScript that provides the implementation for the
validation controls and for performing the postback
70
2006 Pearson Education, Inc. All rights reserved.
157
158 var phoneFormatValidator =
159 document.all ? document.all["phoneFormatValidator"] :
160 document.getElementById("phoneFormatValidator");
161 phoneFormatValidator.controltovalidate = "phoneTextBox";
162 phoneFormatValidator.errormessage =
163 "Please enter a phone number in a \r\n " +
164 " valid format.";
165 phoneFormatValidator.display = "Dynamic";
166 phoneFormatValidator.evaluationfunction =
167 "RegularExpressionValidatorEvaluateIsValid";
168 phoneFormatValidator.validationexpression =
169 "((\\(\\d{3}\\) ?)|(\\d{3}-))?\\d{3}-\\d{4}";
170 // -->
171 </script>
172
173 <div>
174 <input type="hidden" name="__EVENTTARGET"
175 id="__EVENTTARGET" value="" />
176 <input type="hidden" name="__EVENTARGUMENT"
177 id="__EVENTARGUMENT" value="" />
178 </div>
179
180 <script type="text/javascript">
181 <!--
182 var theForm = document.forms['form1'];
183
184 if (!theForm) {
185 theForm = document.form1;
186 }
Outline
Validation.html
(7 of 9)
ECMAScript that provides the implementation for the
validation controls and for performing the postback
71
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187
188 function __doPostBack(eventTarget, eventArgument) {
189 if (!theForm.onsubmit || (theForm.onsubmit() != false)) {
190 theForm.__EVENTTARGET.value = eventTarget;
191 theForm.__EVENTARGUMENT.value = eventArgument;
192 theForm.submit();
193 }
194 }
195 // -->
196 </script>
197
198 <script src="/Validation/WebResource.axd?d=2vO6TLcUQjFB3X5GN16w
199 bg2&t=632494248729409088" type="text/javascript"></script>
200
201 <script type="text/javascript">
202 <!--
203 var Page_ValidationActive = false;
204
205 if (typeof(ValidatorOnLoad) == "function") {
206 ValidatorOnLoad();
207 }
Outline
Validation.html
(8 of 9)
ECMAScript that provides the implementation for the
validation controls and for performing the postback
72
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208
209 function ValidatorOnSubmit() {
210 if (Page_ValidationActive) {
211 return ValidatorCommonOnSubmit();
212 }
213 else {
214 return true;
215 }
216 }
217 // -->
218 </script>
219 </form>
220 </body>
221 </html>
Outline
Validation.html
(9 of 9)
ECMAScript that provides the implementation for the
validation controls and for performing the postback
73
2006 Pearson Education, Inc. All rights reserved.
21.6 Session Tracking
• Session Tracking – Tracking individual clients– The request/response system on which the Web operates is
facilitated by HTTP• HTTP is a stateless protocol
– Does not support persistent connections • Web servers cannot maintain state information regarding
particular clients
– A session represents a unique client on a Web site• The client will still be recognized as the same user if the client leaves
a site and returns later– Each client must identify itself to the server
• Help the server distinguish among clients
74
2006 Pearson Education, Inc. All rights reserved.
21.6.1 Cookies
• Cookies– Piece of data stored in a small text file on the user’s computer
• Maintains information about the client during and between browser sessions
– Are sent and received as a collection of type HttpCookieCollection
– Web Forms can examine the cookies it sent to the client during previous communications
– The expiration date determines how long the cookie remains on the client’s computer
• The Web browser maintains the cookie for the duration of the browsing session if there is no expiration date
– Response object’s Cookies property • Used to write cookies to a client• Used to access cookies
– Can be read by an application only if they were created in the domain in which the application is running
75
2006 Pearson Education, Inc. All rights reserved.
Portability Tip 21.3
Clients may disable cookies in their Web browsers to ensure that their privacy is protected. Such clients will experience difficulty using Web applications that depend on cookies to maintain state information.
76
2006 Pearson Education, Inc. All rights reserved.
1 <%-- Fig. 21.23: Options.aspx --%>
2 <%-- Allows client to select programming languages and access --%>
3 <%-- book recommendations. --%>
4 <%@ Page Language="C#" AutoEventWireup="true"
5 CodeFile="Options.aspx.cs" Inherits="Options" %>
6
7 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
8 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
9
10 <html xmlns="http://www.w3.org/1999/xhtml" >
11 <head runat="server">
12 <title>Cookies</title>
13 </head>
14 <body>
15 <form id="form1" runat="server">
16 <div>
17 <asp:Label ID="promptLabel" runat="server" Font-Bold="True"
18 Font-Size="Large" Text="Select a programming language:">
19 </asp:Label>
20
21 <asp:RadioButtonList ID="languageList" runat="server">
22 <asp:ListItem>Visual Basic 2005</asp:ListItem>
23 <asp:ListItem>Visual C# 2005</asp:ListItem>
24 <asp:ListItem>C</asp:ListItem>
25 <asp:ListItem>C++</asp:ListItem>
26 <asp:ListItem>Java</asp:ListItem>
27 </asp:RadioButtonList>
28
29 <asp:Button ID="submitButton" runat="server" Text="Submit" />
Outline
Options.aspx
(1 of 4)
Declare a RadioButtonList with 5 elements
77
2006 Pearson Education, Inc. All rights reserved.
30
31 <asp:Label ID="responseLabel" runat="server" Font-Bold="True"
32 Font-Size="Large" Text="Welcome to cookies!"
33 Visible="False"></asp:Label>
34 <br /><br />
35
36 <asp:HyperLink ID="languageLink" runat="server"
37 Visible="False" NavigateUrl="~/Options.aspx">
38 Click here to choose another language</asp:HyperLink>
39 <br /><br />
40
41 <asp:HyperLink ID="recommendationsLink" runat="server"
42 Visible="False" NavigateUrl="~/Recommendations.aspx">
43 Click here to get book recommendations</asp:HyperLink>
44 </div>
45 </form>
46 </body>
47 </html>
Outline
Options.aspx
(2 of 4)
Declare two hyperlinks
Does not cause a postback to occur
80
2006 Pearson Education, Inc. All rights reserved.
1 // Fig. 21.24: Options.aspx.cs
2 // Processes user's selection of a programming language
3 // by displaying links and writing a cookie to the user's machine.
4 using System;
5 using System.Data;
6 using System.Configuration;
7 using System.Web;
8 using System.Web.Security;
9 using System.Web.UI;
10 using System.Web.UI.WebControls;
11 using System.Web.UI.WebControls.WebParts;
12 using System.Web.UI.HtmlControls;
13 public partial class Options : System.Web.UI.Page
14 {
15 // stores values to represent books as cookies
16 private System.Collections.Hashtable books =
17 new System.Collections.Hashtable();
18
19 // initializes the Hashtable of values to be stored as cookies
20 protected void Page_Init( object sender, EventArgs e )
21 {
22 books.Add( "Visual Basic 2005", "0-13-186900-0" );
23 books.Add( "Visual C# 2005", "0-13-152523-9" );
24 books.Add( "C", "0-13-142644-3" );
25 books.Add( "C++", "0-13-185757-6" );
26 books.Add( "Java", "0-13-148398-6" );
27 } // end method Page_Init
Outline
Options.aspx.cs
(1 of 3)
A data structure to hold book representations
Add each book element into the hash table
81
2006 Pearson Education, Inc. All rights reserved.
28
29 // if postback, hide form and display links to make additional
30 // selections or view recommendations
31 protected void Page_Load( object sender, EventArgs e )
32 {
33 if ( IsPostBack )
34 {
35 // user has submitted information, so display message
36 // and appropriate hyperlinks
37 responseLabel.Visible = true;
38 languageLink.Visible = true;
39 recommendationsLink.Visible = true;
40
41 // hide other controls used to make language selection
42 promptLabel.Visible = false;
43 languageList.Visible = false;
44 submitButton.Visible = false;
45
46 // if the user made a selection, display it in responseLabel
47 if ( languageList.SelectedItem != null )
48 responseLabel.Text += " You selected " +
49 languageList.SelectedItem.Text.ToString();
50 else
51 responseLabel.Text += " You did not select a language.";
52 } // end if
53 } // end method Page_Load
Outline
Options.aspx.cs
(2 of 3)
Determine whether user selected a language
Display the appropriate output
82
2006 Pearson Education, Inc. All rights reserved.
54
55 // write a cookie to record the user's selection
56 protected void submitButton_Click( object sender, EventArgs e )
57 {
58 // if the user made a selection
59 if ( languageList.SelectedItem != null )
60 {
61 string language = languageList.SelectedItem.ToString();
62
63 // get ISBN number of book for the given language
64 string ISBN = books[ language ].ToString();
65
66 // create cookie using language-ISBN name-value pair
67 HttpCookie cookie = new HttpCookie( language, ISBN );
68
69 // add cookie to response to place it on the user's machine
70 Response.Cookies.Add( cookie );
71 } // end if
72 } // end method submitButton_Click
73 } // end class Options
Outline
Options.aspx.cs
(3 of 3)Retrieve the value that corresponds to the key
contained in language
A new cookie object is created to store the language and its
corresponding ISBN number
The cookie is added to the Cookies collection sent as part
of the HTTP response header
83
2006 Pearson Education, Inc. All rights reserved.
1 <%-- Fig. 21.25: Recommendations.aspx --%>
2 <%-- Displays book recommendations using cookies. --%>
3 <%@ Page Language="C#" AutoEventWireup="true"
4 CodeFile="Recommendations.aspx.cs" Inherits="Recommendations" %>
5
6 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
7 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
8
9 <html xmlns="http://www.w3.org/1999/xhtml" >
10 <head runat="server">
11 <title>Book Recommendations</title>
12 </head>
13 <body>
14 <form id="form1" runat="server">
15 <div>
16 <asp:Label ID="recommendationsLabel"
17 runat="server" Text="Recommendations"
18 Font-Bold="True" Font-Size="X-Large">
19 </asp:Label><br /><br />
20
21 <asp:ListBox ID="booksListBox" runat="server" Height="125px"
22 Width="450px"></asp:ListBox><br /><br />
Outline
Recommendations.aspx
(1 of 2)
Display the recommendations created by the code-behind file
84
2006 Pearson Education, Inc. All rights reserved.
23
24 <asp:HyperLink ID="languageLink" runat="server"
25 NavigateUrl="~/Options.aspx">
26 Click here to choose another language
27 </asp:HyperLink>
28 </div>
29 </form>
30 </body>
31 </html>
Outline
Recommendations.aspx
(2 of 2)
85
2006 Pearson Education, Inc. All rights reserved.
1 // Fig. 21.26: Recommendations.aspx.cs
2 // Creates book recommendations based on cookies.
3 using System;
4 using System.Data;
5 using System.Configuration;
6 using System.Collections;
7 using System.Web;
8 using System.Web.Security;
9 using System.Web.UI;
10 using System.Web.UI.WebControls;
11 using System.Web.UI.WebControls.WebParts;
12 using System.Web.UI.HtmlControls;
13
14 public partial class Recommendations : System.Web.UI.Page
15 {
16 // read cookies and populate ListBox with any book recommendations
17 protected void Page_Init( object sender, EventArgs e )
18 {
19 // retrieve client's cookies
20 HttpCookieCollection cookies = Request.Cookies;
21
22 // if there are cookies, list the appropriate books and ISBN numbers
23 if ( cookies.Count != 0 )
24 {
25 for ( int i = 0; i < cookies.Count; i++ )
26 booksListBox.Items.Add( cookies[ i ].Name +
27 " How to Program. ISBN#: " + cookies[ i ].Value );
28 } // end if
Outline
Recommendations.aspx.cs
(1 of 2)
Retrieves the cookies from the client
Add the information in the cookie(s) to the booksListBox
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29 else
30 {
31 // if there are no cookies, then no language was chosen, so
32 // display appropriate message and clear and hide booksListBox
33 recommendationsLabel.Text = "No Recommendations";
34 booksListBox.Items.Clear();
35 booksListBox.Visible = false;
36
37 // modify languageLink because no language was selected
38 languageLink.Text = "Click here to choose a language";
39 } // end else
40 } // end method Page_Init
41 } // end class Recommendations
Outline
Recommendations.aspx.cs
(2 of 2)
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Fig. 21.27 | HttpCookie properties.
Properties Description
Domain Returns a string containing the cookie’s domain (i.e., the domain of the Web server running the application that wrote the cookie). This determines which Web servers can receive the cookie. By default, cookies are sent to the Web server that originally sent the cookie to the client. Changing the Domain property causes the cookie to be returned to a Web server other than the one that originally wrote it.
Expires Returns a DateTime object indicating when the browser can delete the cookie.
Name Returns a string containing the cookie’s name.
Path Returns a string containing the path to a directory on the server (i.e., the Domain) to which the cookie applies. Cookies can be “targeted” to specific directories on the Web server. By default, a cookie is returned only to applications operating in the same directory as the application that sent the cookie or a subdirectory of that directory. Changing the Path property causes the cookie to be returned to a directory other than the one from which it was originally written.
Secure Returns a bool value indicating whether the cookie should be transmitted through a secure protocol. The value true causes a secure protocol to be used.
Value Returns a string containing the cookie’s value.
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21.6.2 Session Tracking with HttpSessionState
• Class HttpSessionState– Provides session-tracking
– Every Web Form includes an HttpSessionState object• Accessible through property Session of class Page
– Can store name–value pairs using method Add– When adding an attribute that has the same name, the object
associated with that attribute is replaced
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21.6.2 Session Tracking with HttpSessionState (Cont.)
– Property SessionID • Contains the unique session ID
– A sequence of random letters and numbers• The first time a client connects to server, a unique session ID is
created for that client
– Property Timeout • Specifies the maximum amount of time that an HttpSessionState
object can be inactive before it is discarded
– Property Count• Provides the number of session items contained in a Session object
– Property Keys • Returns a collection containing all the session’s keys
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1 <%-- Fig. 21.28: Options.aspx --%>
2 <%-- Allows client to select programming languages and access --%>
3 <%-- book recommendations. --%>
4 <%@ Page Language="C#" AutoEventWireup="true"
5 CodeFile="Options.aspx.cs" Inherits="Options" %>
6
7 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
8 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
9
10 <html xmlns="http://www.w3.org/1999/xhtml" >
11 <head runat="server">
12 <title>Sessions</title>
13 </head>
14 <body>
15 <form id="form1" runat="server">
16 <div>
17 <asp:Label ID="promptLabel" runat="server" Font-Bold="True"
18 Font-Size="Large" Text="Select a programming language:">
19 </asp:Label>
20
21 <asp:RadioButtonList ID="languageList" runat="server">
22 <asp:ListItem>Visual Basic 2005</asp:ListItem>
23 <asp:ListItem>Visual C# 2005</asp:ListItem>
24 <asp:ListItem>C</asp:ListItem>
25 <asp:ListItem>C++</asp:ListItem>
26 <asp:ListItem>Java</asp:ListItem>
27 </asp:RadioButtonList>
28
29 <asp:Button ID="submitButton" runat="server" Text="Submit" />
Outline
Options.aspx
(1 of 4)
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30
31 <asp:Label ID="responseLabel" runat="server" Font-Bold="True"
32 Font-Size="Large" Text="Welcome to sessions!"
33 Visible="False"></asp:Label><br /><br />
34
35 <asp:Label ID="idLabel" runat="server" Visible="False">
36 </asp:Label><br /><br />
37
38 <asp:Label ID="timeoutLabel" runat="server" Visible="False">
39 </asp:Label><br /><br />
40
41 <asp:HyperLink ID="languageLink" runat="server"
42 Visible="False" NavigateUrl="~/Options.aspx">
43 Click here to choose another language
44 </asp:HyperLink><br /><br />
45
46 <asp:HyperLink ID="recommendationsLink" runat="server"
47 Visible="False" NavigateUrl="~/Recommendations.aspx">
48 Click here to get book recommendations</asp:HyperLink>
49 </div>
50 </form>
51 </body>
52 </html>
Outline
Options.aspx
(2 of 4)
Hidden labels to display tracking information
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Software Engineering Observation 21.1
A Web Form should not use instance variables to maintain client state information, because each new request or postback, is handled by a new instance of the page. Web Forms should maintain client state information in HttpSessionState objects, because such objects are specific to each client.
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1 // Fig. 21.29: Options.aspx.cs
2 // Processes user's selection of a programming language
3 // by displaying links and writing a cookie to the user's machine.
4 using System;
5 using System.Data;
6 using System.Configuration;
7 using System.Web;
8 using System.Web.Security;
9 using System.Web.UI;
10 using System.Web.UI.WebControls;
11 using System.Web.UI.WebControls.WebParts;
12 using System.Web.UI.HtmlControls;
13 public partial class Options : System.Web.UI.Page
14 {
15 // stores values to represent books as cookies
16 private System.Collections.Hashtable books =
17 new System.Collections.Hashtable();
18
19 //initializes the Hashtable of values to be stored as cookies
20 protected void Page_Init( object sender, EventArgs e )
21 {
22 books.Add( "Visual Basic 2005", "0-13-186900-0" );
23 books.Add( "Visual C# 2005", "0-13-152523-9" );
24 books.Add( "C", "0-13-142644-3" );
25 books.Add( "C++", "0-13-185757-6" );
26 books.Add( "Java", "0-13-148398-6" );
27 } // end method Page_Init
Outline
Options.aspx.cs
(1 of 3)
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28
29 // if postback, hide form and display links to make additional
30 // selections or view recommendations
31 protected void Page_Load( object sender, EventArgs e )
32 {
33 if ( IsPostBack )
34 {
35 // user has submitted information, so display appropriate labels
36 // and hyperlinks
37 responseLabel.Visible = true;
38 idLabel.Visible = true;
39 timeoutLabel.Visible = true;
40 languageLink.Visible = true;
41 recommendationsLink.Visible = true;
42
43 // hide other controls used to make language selection
44 promptLabel.Visible = false;
45 languageList.Visible = false;
46 submitButton.Visible = false;
47
48 // if the user made a selection, display it in responseLabel
49 if ( languageList.SelectedItem != null )
50 responseLabel.Text += " You selected " +
51 languageList.SelectedItem.Text.ToString();
52 else
53 responseLabel.Text += " You did not select a language.";
54
55 // display session ID
56 idLabel.Text = "Your unique session ID is: " + Session.SessionID;
Outline
Options.aspx.cs
(2 of 3)
Returns the unique session ID
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57
58 // display the timeout
59 timeoutLabel.Text = "Timeout: " + Session.Timeout + " minutes.";
60 } // end if
61 } // end method Page_Load
62
63 // write a cookie to record the user's selection
64 protected void submitButton_Click( object sender, EventArgs e )
65 {
66 // if the user made a selection
67 if ( languageList.SelectedItem != null )
68 {
69 string language = languageList.SelectedItem.ToString();
70
71 // get ISBN number of book for the given language
72 string ISBN = books[ language ].ToString();
73
74 Session.Add( language, ISBN ); // add name/value pair to Session
75 } // end if
76 } // end method submitButton_Click
77 } // end class Options
Outline
Options.aspx.cs
(3 of 3)
Returns the maximum amount of time that an HttpSessionState object can be inactive before it is discarded
Place the language and its corresponding ISBN number in the HttpSessionState object
98
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Software Engineering Observation 21.2
One of the primary benefits of using HttpSessionState objects (rather than cookies) is that HttpSessionState objects can store any type of object (not just Strings) as attribute values. This provides you with increased flexibility in determining the type of state information to maintain for clients.
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Fig. 21.30 | HttpSessionState properties.
Properties Description
Count Specifies the number of key–value pairs in the Session object.
IsNewSession Indicates whether this is a new session (i.e., whether the session was created during loading of this page).
IsReadOnly Indicates whether the Session object is read-only.
Keys Returns a collection containing the Session object’s keys.
SessionID Returns the session’s unique ID.
Timeout Specifies the maximum number of minutes during which a session can be inactive (i.e., no requests are made) before the session expires. By default, this property is set to 20 minutes.
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1 <%-- Fig. 21.31: Recommendations.aspx --%>
2 <%-- Displays book recommendations using sessions. --%>
3 <%@ Page Language="C#" AutoEventWireup="true"
4 CodeFile="Recommendations.aspx.cs" Inherits="Recommendations" %>
5
6 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
7 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
8
9 <html xmlns="http://www.w3.org/1999/xhtml" >
10 <head runat="server">
11 <title>Book Recommendations</title>
12 </head>
13 <body>
14 <form id="form1" runat="server">
15 <div>
16 <asp:Label ID="recommendationsLabel"
17 runat="server" Text="Recommendations"
18 Font-Bold="True" Font-Size="X-Large">
19 </asp:Label><br /><br />
20
21 <asp:ListBox ID="booksListBox" runat="server" Height="125px"
22 Width="450px"></asp:ListBox><br /><br />
Outline
Recommendations.aspx
(1 of 2)
Used to present the recommendations to the user
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23
24 <asp:HyperLink ID="languageLink" runat="server"
25 NavigateUrl="~/Options.aspx">
26 Click here to choose another language
27 </asp:HyperLink>
28 </div>
29 </form>
30 </body>
31 </html>
Outline
Recommendations.aspx
(2 of 2)
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1 // Fig. 21.32: Recommendations.aspx.cs
2 // Creates book recommendations based on a session object.
3 using System;
4 using System.Data;
5 using System.Configuration;
6 using System.Collections;
7 using System.Web;
8 using System.Web.Security;
9 using System.Web.UI;
10 using System.Web.UI.WebControls;
11 using System.Web.UI.WebControls.WebParts;
12 using System.Web.UI.HtmlControls;
13
14 public partial class Recommendations : System.Web.UI.Page
15 {
16 // read cookies and populate ListBox with any book recommendations
17 protected void Page_Init( object sender, EventArgs e )
18 {
19 // stores a key name found in the Session object
20 string keyName;
21
22 // determine whether Session contains any information
23 if ( Session.Count != 0 )
24 {
25 for ( int i = 0; i < Session.Count; i++ )
26 {
27 keyName = Session.Keys[ i ]; // store current key name
Outline
Recommendations.aspx.cs
(1 of 2)
Provides the number of session items contained in
a Session object
Indexes the collection containing all the keys in the session to
receive the current key
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28
29 // use current key to display one
30 // of session's name-value pairs
31 booksListBox.Items.Add( keyName +
32 " How to Program. ISBN#: " +
33 Session[ keyName ].ToString() );
34 } // end for
35 } // end if
36 else
37 {
38 // if there are no session items, no language was chosen, so
39 // display appropriate message and clear and hide booksListBox
40 recommendationsLabel.Text = "No Recommendations";
41 booksListBox.Items.Clear();
42 booksListBox.Visible = false;
43
44 // modify languageLink because no language was selected
45 languageLink.Text = "Click here to choose a language";
46 } // end else
47 } // end method Page_Init
48 } // end class Recommendations
Outline
Recommendations.aspx.cs
(2 of 2)
Concatenate and display the string that is the recommendation in the
ListBox
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21.7.1 Building a Web Form That Displays Data from a Database
• Step 1: Creating the Project
• Step 2: Creating the Form for User Input (Fig. 21.33)
• Step 3: Adding a GridView Control to the Web Form
• Step 4: Adding a Database to an ASP.NET Web Application
– Database used by an ASP.NET Web site should be located in the project’s App_Data folder
• Step 5: Binding the GridView to the Messages Table of the Guestbook Database (Fig. 21.34-37)
• Step 6: Modifying the Columns of the Data Source Displayed in the GridView (Fig. 21.38)
• Step 7: Modifying the Way the SqlDataSource Control Inserts Data (Fig. 21.39)
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Fig. 21.33 | Guestbook application GUI in Design mode.
GridView control
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Fig. 21.34 | Change Data Source dialog in Visual Web Developer.
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Fig. 21.35 | Configuring the SELECT statement used by the SqlDataSource to retrieve data.
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Fig. 21.36 | Previewing the data retrieved by the SqlDataSource.
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Fig. 21.37 | Design mode displaying SqlDataSource control for a GridView.
SqlDataSource control
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Fig. 21.38 | Removing the MessageID column from the GridView.
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Fig. 21.39 | Setting up INSERT parameters based on control values.
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21.7.1 Building a Web Form That Displays Data from a Database (Cont.)
•GridView – DataSourceID property
• Identifies the data source that is used to fill the GridView with data at runtime
– HeaderText property • Indicates the text that appears as the column header
– By default, this is the name of the column in the data source
– Each column is represented as a BoundField
113
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21.7.1 Building a Web Form That Displays Data from a Database (Cont.)
• SqlDataSource– ConnectionString property
• Indicates the connection that the SqlDataSource control interacts with • The value of this property uses an ASP.NET expression, delimited by <%$
and %>
– SelectCommand, DeleteCommand, InsertCommand and UpdateCommand properties
• Contain the SELECT, DELETE, INSERT and UPDATE SQL statements, respectively
– Parameters that are set programmatically are defined by Parameter elements
– Parameters that obtain their values from controls are defined by ControlParameter elements
114
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1 <%-- Fig. 21.40: Guestbook.aspx --%>
2 <%-- Guestbook Web application with a form for users to submit --%>
3 <%-- guestbook entries and a GridView to view existing entries. --%>
4 <%@ Page Language="C#" AutoEventWireup="true"
5 CodeFile="Guestbook.aspx.cs" Inherits="Guestbook" %>
6
7 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
8 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
9
10 <html xmlns="http://www.w3.org/1999/xhtml" >
11 <head runat="server">
12 <title>Guestbook</title>
13 </head>
14 <body>
15 <form id="form1" runat="server">
16 <div>
17 <h2><span style="color: navy">
18 Please leave a message in our guestbook:</span></h2>
19
20 <table>
21 <tr>
22 <td style="width: 130px; height: 21px" valign="top">
23 Your name:<br />
24 </td>
25 <td style="width: 300px; height: 21px" valign="top">
26 <asp:TextBox ID="nameTextBox" runat="server"
27 Width="300px"></asp:TextBox>
28 </td>
29 </tr>
Outline
Guestbook.aspx
(1 of 7)
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30 <tr>
31 <td style="width: 130px" valign="top">
32 Your e-mail address:<br />
33 </td>
34 <td style="width: 300px" valign="top">
35 <asp:TextBox ID="emailTextBox" runat="server"
36 Width="300px"></asp:TextBox></td>
37 </tr>
38 <tr>
39 <td style="width: 130px" valign="top">
40 Tell the world:<br />
41 </td>
42 <td style="width: 300px" valign="top">
43 <asp:TextBox ID="messageTextBox" runat="server"
44 Height="100px" Rows="8" Width="300px">
45 </asp:TextBox>
46 </td>
47 </tr>
48 <tr>
49 <td style="width: 130px" valign="top">
50 </td>
51 <td style="width: 300px" valign="top">
52 <asp:Button ID="submitButton" runat="server"
53 Text="Submit" />
54 <asp:Button ID="clearButton" runat="server"
55 Text="Clear" />
56 </td>
57 </tr>
58 </table>
59 <br />
Outline
Guestbook.aspx
(2 of 7)
116
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60
61 <asp:GridView ID="messagesGridView" runat="server"
62 AutoGenerateColumns="False" CellPadding="4"
63 ForeColor="#333333" GridLines="None"
64 DataSourceID="messagesSqlDataSource" Width="600px"
65 DataKeyNames="MessageID">
66 <FooterStyle BackColor="#1C5E55" Font-Bold="True"
67 ForeColor="White" />
68 <RowStyle BackColor="#E3EAEB" />
69 <PagerStyle BackColor="#666666" ForeColor="White"
70 HorizontalAlign="Center" />
71 <SelectedRowStyle BackColor="#C5BBAF" Font-Bold="True"
72 ForeColor="#333333" />
73 <HeaderStyle BackColor="#1C5E55" Font-Bold="True"
74 ForeColor="White" />
75 <EditRowStyle BackColor="#7C6F57" />
76 <AlternatingRowStyle BackColor="White" />
Outline
Guestbook.aspx
(3 of 7)
Declare the GridView control
Identifies the data source that is used to fill the GridView
with data at runtime
Properties that set various aspects of the GridView’s
appearance and behavior
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77 <Columns>
78 <asp:BoundField DataField="Date" HeaderText="Date"
79 SortExpression="Date" />
80 <asp:BoundField DataField="Name" HeaderText="Name"
81 SortExpression="Name" />
82 <asp:BoundField DataField="Email" HeaderText="Email"
83 SortExpression="Email" />
84 <asp:BoundField DataField="Message" HeaderText="Message"
85 SortExpression="Message" />
86 </Columns>
87 </asp:GridView>
88
89 <asp:SqlDataSource ID="messagesSqlDataSource" runat="server"
90 ConnectionString=
91 "<%$ ConnectionStrings:GuestbookConnectionString %>"
92 SelectCommand="SELECT * FROM [Messages]"
93 DeleteCommand="DELETE FROM [Messages] WHERE
94 [MessageID] = @original_MessageID"
95 InsertCommand="INSERT INTO [Messages]
96 ([Date], [Name], [Email], [Message]) VALUES
97 (@Date, @Name, @Email, @Message)"
98 UpdateCommand="UPDATE [Messages] SET [Date] = @Date,
99 [Name] = @Name, [Email] = @Email, [Message] = @Message
100 WHERE [MessageID] = @original_MessageID">
101 <DeleteParameters>
102 <asp:Parameter Name="original_MessageID" Type="Int32" />
103 </DeleteParameters>
Outline
Guestbook.aspx
(4 of 7)
Define the columns that appear in the GridView
Each BoundField represents a column
Define a SqlDataSource
control
Indicates the connection through which the
SqlDataSource control interacts which the database
Defines SQL command statements
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104 <UpdateParameters>
105 <asp:Parameter Name="Date" Type="String" />
106 <asp:Parameter Name="Name" Type="String" />
107 <asp:Parameter Name="Email" Type="String" />
108 <asp:Parameter Name="Message" Type="String" />
109 <asp:Parameter Name="original_MessageID" Type="Int32" />
110 </UpdateParameters>
111 <InsertParameters>
112 <asp:Parameter Name="Date" Type="String" />
113 <asp:ControlParameter ControlID="nameTextBox"
114 Name="Name" PropertyName="Text" Type="String" />
115 <asp:ControlParameter ControlID="emailTextBox"
116 Name="Email" PropertyName="Text" Type="String" />
117 <asp:ControlParameter ControlID="messageTextBox"
118 Name="Message" PropertyName="Text" Type="String" />
119 </InsertParameters>
120 </asp:SqlDataSource>
121 </div>
122 </form>
123 </body>
124 </html>
Outline
Guestbook.aspx
(5 of 7)
Indicates the control from which the parameter gets its value
Specifies the property that contains the actual value to be
used as the parameter valueParameters that obtain their values from controls
Parameters that are set programmatically
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21.7.2 Modifying the Code-Behind File for the Guestbook Application
•SqlDataSource– InsertParameters collection
• Contains an item corresponding to each parameter in the SqlDataSource’s INSERT command
– Insert method • Executes the control’s INSERT command against the
database
•GridView method DataBind – Refreshes the information displayed in the GridView
122
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1 // Fig. 21.41: Guestbook.aspx.cs
2 // Code-behind file that defines event handlers for the guestbook.
3 using System;
4 using System.Data;
5 using System.Configuration;
6 using System.Web;
7 using System.Web.Security;
8 using System.Web.UI;
9 using System.Web.UI.WebControls;
10 using System.Web.UI.WebControls.WebParts;
11 using System.Web.UI.HtmlControls;
12
13 public partial class Guestbook : System.Web.UI.Page
14 {
15 // Submit Button adds a new guestbook entry to the database,
16 // clears the form and displays the updated list of guestbook entries
17 protected void submitButton_Click( object sender, EventArgs e )
18 {
19 // create a date parameter to store the current date
20 System.Web.UI.WebControls.Parameter date =
21 new System.Web.UI.WebControls.Parameter(
22 "Date", TypeCode.String, DateTime.Now.ToShortDateString() );
23
24 // set the @Date parameter to the date parameter
25 messagesSqlDataSource.InsertParameters.RemoveAt( 0 );
26 messagesSqlDataSource.InsertParameters.Add( date );
Outline
Guestbook.aspx.cs
(1 of 2)
Assign a string representation of the current data to a new object of type Parameter
Remove the Date item in the InsertParameters
collection
Add our Date parameter
123
2006 Pearson Education, Inc. All rights reserved.
27
28 // execute an INSERT SQL statement to add a new row to the
29 // Messages table in the Guestbook database that contains the
30 // current date and the user's name, e-mail address and message
31 messagesSqlDataSource.Insert();
32
33 // clear the TextBoxes
34 nameTextBox.Text = "";
35 emailTextBox.Text = "";
36 messageTextBox.Text = "";
37
38 // update the GridView with the new database table contents
39 messagesGridView.DataBind();
40 } // end method submitButton_Click
41
42 // Clear Button clears the Web Form's TextBoxes
43 protected void clearButton_Click( object sender, EventArgs e )
44 {
45 nameTextBox.Text = "";
46 emailTextBox.Text = "";
47 messageTextBox.Text = "";
48 } // end method clearButton_Click
49 } // end class Guestbook
Outline
Guestbook.aspx.cs
(2 of 2)
Executes the INSERT command against the database: add a row to the Messages table
124
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21.8.1 Examining the Completed Secure Books Database Application
• Form authentication– Protect a page so that only users known to the site can
access it
• Example of visual inheritance:– Master page defines common GUI elements that are
inherited by each page in a set of content pages
125
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Fig. 21.42 | Login.aspx page of the secure books database application.
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2006 Pearson Education, Inc. All rights reserved.
Fig. 21.43 | CreateNewUser.aspx page of the secure book database application.
127
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Fig. 21.44 | Message displayed to indicate that a user account was created successfully.
128
2006 Pearson Education, Inc. All rights reserved.
Fig. 21.45 | Books.aspx displaying books by Harvey Deitel (by default).
129
2006 Pearson Education, Inc. All rights reserved.
Fig. 21.46 | Books.aspx displaying books by Andrew Goldberg.
130
2006 Pearson Education, Inc. All rights reserved.
Fig. 21.47 | Logging in using the Login control.
131
2006 Pearson Education, Inc. All rights reserved.
21.8.2 Creating the Secure Books Database Application
• Step 1: Creating the Web Site
• Step 2: Setting Up the Web Site’s Folders
• Step 3: Configuring the Application’s Security Settings (Fig. 21.49-53)
– Access rule grants or denies access to a particular Web application directory for a specific user
• Step 4: Examining the Auto-Generated Web.config Files
– authorization element indicates who is authorized to access a folder over the Web
– mode attribute species that we want to use forms authentication
– deny element specifies the users to whom we wish to deny access
• Step 5: Creating a Master Page (Fig. 21.54-56)
– Master directive specifies that this file defines a master page
– script element stores the code that is usually in the code behind file
– ContentPlaceHolder control serves as a placeholder for content that will be defined
132
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21.8.2 Creating the Secure Books Database Application (Cont.)
• Step 6: Creating a Content Page (Fig. 21.57-58)
– Content control will place page-specific content that will replace the master page’s ContentPlaceHolder
• Step 7: Adding a CreateUserWizard Control to a Content Page (Fig. 21.59)
• Step 8: Creating a Login Page (Fig. 21.60)
– ASP.NET writes an encrypted cookie containing data about an authenticated user
– Authenticated user is redirected to the page specified by the Login control’s DestinationPageUrl property
• Step 9: Creating a Content Page That Only Authenticated Users Can Access
• Step 10: Customizing the Secure Page
– LoginName control displays the current authenticated user name
133
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21.8.2 Creating the Secure Books Database Application (Cont.)
• Step 11: Connecting the CreateUserWizard and Login Controls to the Secure Page
• Step 12: Generating a DataSet Based on the Books.mdf Database
– ObjectDataSource encapsulates an object that provides access to a data source
• Step 13: Creating and Configuring an AuthorsTableAdapter (Fig. 21.61)
• Step 14: Creating and Configuring a TitlesTableAdapter (Fig. 21.62-63)
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21.8.2 Creating the Secure Books Database Application (Cont.)
• Step 15: Adding a DropDownList Containing Authors’ First and Last Names (Fig. 21.64-66)
– A business object is an object that accesses data through another object
– DropDownList’s AutoPostBack property indicates that a postback occurs each time the user selects an item
• Step 16: Creating a GridView to Display the Selected Author’s Books (Fig. 21.67-68)
– Enable Sorting causes the column headings in the GridView to turn into hyperlinks that allow users to sort the data
– Enable Paging causes the GridView to split across multiple pages
– PageSize property determines the number of entries per page
• Step 17: Examining the Markup in Books.aspx (Fig. 21.69)
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Fig. 21.48 | Error message displayed for an unsuccessful login attempt using the Login control.
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Fig. 21.49 | Web Site Administration Tool for configuring a Web application.
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Fig. 21.50 | Security page of the Web Site Administration Tool.
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Fig. 21.51 | Choosing the type of authentication used by an ASP.NET Web application.
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Fig. 21.52 | Main page of the Web Site Administration Tool after enabling forms authentication.
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Fig. 21.53 | Add New Access Rule page used to configure directory access.
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1 <%-- Fig. 21.56: Bug2Bug.master --%>
2 <%-- Master page that defines common features of all pages in the --%>
3 <%-- secure book database application. --%>
4 <%@ Master Language="C#" %>
5
6 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
7 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
8
9 <html xmlns="http://www.w3.org/1999/xhtml" >
10 <head runat="server">
11 <title>Bug2Bug</title>
12 </head>
13 <body>
14 <form id="form1" runat="server">
15 <div>
16 <table border="0" cellpadding="0" cellspacing="0"
17 style="width: 100%; height: 100%">
18 <tr>
19 <td height="130">
20 <asp:Image ID="headerImage" runat="server"
21 ImageUrl="~/Images/bug2bug.png" />
22 </td>
23 </tr>
Outline
Bug2Bug.master
(1 of 2)
Specify the language is C#
Display logo picture
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24 <tr>
25 <td valign="top">
26 <asp:contentplaceholder id="bodyContent"
27 runat="server">
28 </asp:contentplaceholder>
29 </td>
30 </tr>
31 </table>
32 </div>
33 </form>
34 </body>
35 </html>
Outline
Bug2Bug.master
(2 of 2)
Define a ContentPlaceHolder
control
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Fig. 21.57 | Content page CreateNewUser.aspx in Source mode.
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Fig. 21.58 | Content page CreateNewUser.aspx in Design mode.
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1 <%-- Fig. 21.59: CreateNewUser.aspx --%>
2 <%-- Content page using a CreateUserWizard control to register users. --%>
3 <%@ Page Language="C#" MasterPageFile="~/Bug2Bug.master"
4 Title="Create a New User" %>
5
6 <asp:Content ID="Content1" ContentPlaceHolderID="bodyContent"
7 Runat="Server">
8
9 <asp:CreateUserWizard ID="CreateUserWizard1" runat="server"
10 BackColor="#F7F6F3" BorderColor="#E6E2D8" BorderStyle="Solid"
11 BorderWidth="1px" Font-Names="Verdana" Font-Size="0.8em"
12 ContinueDestinationPageUrl="~/Secure/Books.aspx">
13
14 <SideBarStyle BackColor="#5D7B9D" BorderWidth="0px"
15 Font-Size="0.9em" VerticalAlign="Top" />
16 <SideBarButtonStyle BorderWidth="0px" Font-Names="Verdana"
17 ForeColor="White" />
18 <NavigationButtonStyle BackColor="#FFFBFF" BorderColor="#CCCCCC"
19 BorderStyle="Solid" BorderWidth="1px" Font-Names="Verdana"
20 ForeColor="#284775" />
21 <HeaderStyle BackColor="#5D7B9D" BorderStyle="Solid"
22 Font-Bold="True" Font-Size="0.9em"
23 ForeColor="White" HorizontalAlign="Left" />
24 <CreateUserButtonStyle BackColor="#FFFBFF" BorderColor="#CCCCCC"
25 BorderStyle="Solid" BorderWidth="1px" Font-Names="Verdana"
26 ForeColor="#284775" />
27 <ContinueButtonStyle BackColor="#FFFBFF" BorderColor="#CCCCCC"
28 BorderStyle="Solid" BorderWidth="1px" Font-Names="Verdana"
29 ForeColor="#284775" />
Outline
CreateNewUser.aspx
(1 of 3)
Specify language, master page, and title
Contains several properties that specify formatting styles for the control
Elements that define additional styles used to format specific
parts of the control
Replaces the master page’s ContentPlaceHolder
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30 <StepStyle BorderWidth="0px" />
31 <TitleTextStyle BackColor="#5D7B9D" Font-Bold="True"
32 ForeColor="White" />
33
34 <WizardSteps>
35 <asp:CreateUserWizardStep runat="server">
36 </asp:CreateUserWizardStep>
37 <asp:CompleteWizardStep runat="server">
38 </asp:CompleteWizardStep>
39 </WizardSteps>
40 </asp:CreateUserWizard>
41 </asp:Content>
Outline
CreateNewUser.aspx
(2 of 3)
(a) (b)
Classes that encapsulate the details of creating a user and issuing a
confirmation message
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1 <%-- Fig. 21.60: Login.aspx --%>
2 <%-- Content page using a Login control that authenticates users. --%>
3 <%@ Page Language="C#" MasterPageFile="~/Bug2Bug.master" Title="Login" %>
4
5 <asp:Content ID="Content1" ContentPlaceHolderID="bodyContent"
6 Runat="Server">
7
8 <asp:Login ID="Login1" runat="server" BackColor="#F7F6F3"
9 BorderColor="#E6E2D8" BorderPadding="4" BorderStyle="Solid"
10 BorderWidth="1px" CreateUserText="Click here to create a new user"
11 CreateUserUrl="~/CreateNewUser.aspx"
12 DestinationPageUrl="~/Secure/Books.aspx" DisplayRememberMe="False"
13 Font-Names="Verdana" Font-Size="0.8em" ForeColor="#333333">
14
15 <LoginButtonStyle BackColor="#FFFBFF" BorderColor="#CCCCCC"
16 BorderStyle="Solid" BorderWidth="1px" Font-Names="Verdana"
17 Font-Size="0.8em" ForeColor="#284775" />
18 <TextBoxStyle Font-Size="0.8em" />
19 <TitleTextStyle BackColor="#5D7B9D" Font-Bold="True"
20 Font-Size="0.9em" ForeColor="White" />
21 <InstructionTextStyle Font-Italic="True" ForeColor="Black" />
22 </asp:Login>
23 </asp:Content>
Outline
Login.aspx
(1 of 2)
Specify language, master page, and title
Replaces the master page’s ContentPlaceHolder
Create a Login control
The elements define various formatting
style applied to parts of the control
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Fig. 21.61 | Authors DataTable in the Dataset Designer.
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Fig. 21.62 | Query Builder for designing a query that selects books written by a particular author.
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Fig. 21.63 | Dataset Designer after adding the TitlesTableAdapter.
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Fig. 21.64 | Choosing a business object for an ObjectDataSource.
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Fig. 21.65 | Choosing a data method of a business object for use with an ObjectDataSource.
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Fig. 21.66 | Choosing a data source for a DropDownList.
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Fig. 21.67 | Choosing the data source for a parameter in a business object’s data method.
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Fig. 21.68 | Completed Books.aspx in Design mode.
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1 <%-- Fig. 21.69: Books.aspx --%>
2 <%-- Displays information from the Books database. --%>
3 <%@ Page Language="C#" MasterPageFile="~/Bug2Bug.master"
4 Title="Book Information" %>
5
6 <asp:Content ID="Content1" ContentPlaceHolderID="bodyContent"
7 Runat="Server">
8
9 Welcome, <asp:LoginName ID="LoginName1" runat="server" />!
10 <asp:LoginStatus ID="LoginStatus1" runat="server"
11 LogoutAction="RedirectToLoginPage"
12 LogoutText="Click here to log out" /><br /><br />
13
14 Author:
15 <asp:DropDownList ID="authorsDropDownList" runat="server"
16 AutoPostBack="True" DataSourceID="authorsObjectDataSource"
17 DataTextField="Name" DataValueField="AuthorID">
18 </asp:DropDownList>
19
20 <asp:ObjectDataSource ID="authorsObjectDataSource"
21 runat="server" SelectMethod="GetData"
22 TypeName="BooksDataSetTableAdapters.AuthorsTableAdapter">
23 </asp:ObjectDataSource><br /><br />
24
25 <asp:GridView ID="titlesGridView" runat="server" AllowPaging="True"
26 AllowSorting="True" AutoGenerateColumns="False" CellPadding="5"
27 DataKeyNames="ISBN" DataSourceID="titlesObjectDataSource"
28 PageSize="4" Width="600px">
Outline
Books.aspx
(1 of 5)
Create a LoginName control; displays the authenticated user’s name when the page is requested
and viewed in a browser
Create a LoginStatus control; redirect user to
login page after logging out
Indicates that changing the selected item in the list
causes a postback to occur
Specifies that this ObjectDataSource
accesses the Books database by calling GetData of BooksDataSet’s
AuthorsTableAdapter
Create the GridView that displays information about the books
written by the selected author
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29
30 <Columns>
31 <asp:BoundField DataField="ISBN"
32 HeaderText="ISBN" ReadOnly="True" SortExpression="ISBN" />
33 <asp:BoundField DataField="Title"
34 HeaderText="Title" SortExpression="Title" />
35 <asp:BoundField DataField="EditionNumber"
36 HeaderText="EditionNumber" SortExpression="EditionNumber" />
37 <asp:BoundField DataField="Copyright"
38 HeaderText="Copyright" SortExpression="Copyright" />
39 </Columns>
40
41 <HeaderStyle BackColor="LightGreen" />
42 <AlternatingRowStyle BackColor="LightYellow" />
43 </asp:GridView>
44
45 <asp:ObjectDataSource ID="titlesObjectDataSource" runat="server"
46 SelectMethod="GetDataByAuthorID"
47 TypeName="BooksDataSetTableAdapters.TitlesTableAdapter">
48
49 <SelectParameters>
50 <asp:ControlParameter ControlID="authorsDropDownList"
51 DefaultValue="1" Name="authorID"
52 PropertyName="SelectedValue" Type="Int32" />
53 </SelectParameters>
54 </asp:ObjectDataSource>
55 </asp:Content>
Outline
Books.aspx
(2 of 5)
Define the ObjectDataSource
used to fill the GridView with data
Specifies that the value of method GetDataByAuthorID’s parameter comes from the
SelectedValue property of authorsDropDownList
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