Introducing ASP.NET 2.0
Internet TechnologiesWWW Architecture
Web Server
Client
Server
Request
Response
Network HTTPTCP/IP
PC/Mac/Unix + Browser (IE, FireFox)
Internet TechnologiesWWW Architecture
Client-side: HTML / XHTML (Extensible HyperText Markup Language) JavaScript / VBScript (client-side scripting) Applets / ActiveX controls
Server-side: PHP JSP (Java Server Pages) ASP (Active Server Pages) ASP.NET (next generation of ASP)
Server-Side Code
What is server-side code? Software that runs on the
server, not the client Receives input from
URL parameters HTML form data
Can access server-side databases, e-mail servers, files, mainframes, etc.
Dynamically builds a custom HTML response for a client
HTTP request(form data,
HTTP header data)
HTTP responseHTML, XML
ASP page(static HTML, server-side logic)
Static vs Dynamic Web Pages
Most Web pages that you view are not static HTML pages
Instead they are dynamic generated content output from programs that run on servers
These programs can interact with server resources like databases and XML Web services
ASP.NET Overview
ASP.NET is a revolutionary programming framework that enables the rapid development of powerful web applications and services
It’s a part of the emerging Microsoft .NET Platform
It provides the easiest and most scalable way to build, deploy and run distributed web applications that can target any browser or device
Why ASP .NET?
Make it easier to build web appsMake it easier to deploy web appsMake it easier to operate web appsProvide greater performance, reliability, and
scalability
ASP .NET Capabilities
1.It’s really, really fast!2.Deploy and upgrade running apps with
XCOPY3.Great tools support4.Automatically detects and recovers from
errors5.Built-in output caching6.Supports wide range of mobile devices7.Uses compiled languages8.Makes building web services easy9.Much simpler page development model
The .NET Framework
.NET Framework is a collection of technologies for the development and deployment of .NET software systems
Common Language Runtime (CLR) Unifies programming models Provides robust and secure execution environment Supports multiple programming languages Provides core services
Memory management (Garbage Collection) Thread management Remoting Manage Code Execution
“Like” Java Runtime Environment (JRE) Code is NOT interpreted by CLR, but managed
Common Language Specification Set of features guaranteed to be in all languages
The .NET Framework
Aim of .NET : seamless interoperability A component in any .NET language can:
Inherit from any other .NET language class Call the methods of any other .NET language class
Benefits of .Net Rich UI Toolkit, even for the web (ASP.Net) Language independence (VB.Net, C#, J#, C++, COBOL,
and others) Standard based (XML, SOAP, HTTP) Interoperability with COM .Net Framework Library
Rich set of classes
The .NET Framework
Common Language Specification
Common Language Runtime
VB C++ C#
ASP.NET: Web Servicesand Web Forms
JScript …
WindowsForms
.NET Framework Base Classes
ADO.NET: Data and XML
Visu
al Stu
dio
.NE
T
Example of ASP.NET
<%@ Page language=“C#"%><HTML>
<Script runat="server">void btnSubmit_OnClick(Object sender, EventArgs e){
lbl1.Text = “Hello World!";}
</Script><body>
<form runat="server"><asp:Label id="lbl1" runat="server" /><br><asp:Button id="btn1" runat="server"
Text="Click" OnClick="btnSubmit_OnClick" /></form>
</body></HTML>
start.aspx ASP.NET Directive Specify used language
Server side script
ASP.NET web formNote one page can have only one web form
ASP.NET web control
Event Handler
Example of ASP.NET
Result
ClickClick
Hello World!
Client Web Browser
Example of ASP.NET
Result
Click
Hello World!
Client Web Browser <asp:Label id="lbl1" runat="server" /><br>
<asp:Button id="btn1" runat="server“ Text="Click" OnClick="btnSubmit_OnClick" />
void btnSubmit_OnClick(Object sender, EventArgs e){
lbl1.Text = “Hello World!";}
ASP.NET server controlBefore user clicks the button,this control is invisible
ASP.NET server controlAll have Id and Text attributesCreate browser-specific HTML
Event handler functionThis function specifies what to dowhen some event occurs.In these case, it changes “lbl1” control’s text
Round trip
start.aspx
Client Browser
lbl1
btn1
Post Data
lbl1=“”submit=btn1
Event occursSend data
Event handler
btnSubmit_OnClick
Server
Event occurs
Example of ASP.NET
ASP.NET Web Forms
An ASP.NET web application: Consists of any number of web pages, controls,
programming classes, web services, and other files Residing within a single web server application directory
The principle component of an ASP.NET web application are its web pages
These are text files with an .aspx extension and are called web forms
Consists of two parts: The declaratively-defined (i.e., by markup/ tags) visual
elements The programming logic
Web Form Programming Logic
A web form’s programming logic can exist in either: The same file as the visual elements
i.e., the .aspx file This code is contained within a code-declaration block
In a separate class file The file is usually called a code-behind file By conversation, its filename is same as .aspx file but
with a language extension HelloWorld.aspx <- web form HelloWorld.aspx.cs <-code-behind file
Why Use Code-Behind?
The real advantage of separating the code into its own file is that it may lead to more maintainable web forms One of the main benefits of ASP.NET is that a page’s
programming logic can be conceptually separated from the presentation
By using a code-behind file a page’s programming logic can also be physically separated from the presentation/markup
Why Use Code-Behind?
By placing the programming code into its own file, it is also potentially easier to make use of a division of labor in the creation of the site
Use whichever model you want However, all the examples in text use code-behind
Web Application Structure
An ASP.NET web application can simply consist of a folder containing web forms and other files
You can add any number of additional nested subfolders within this root folder
ASP.NET has a number of reserved application folder names, e.g. App_Code App_Data App_Theme
