CS360/CS580H

GUI & Windows Programming

Introduction

Basic Course Outline

• Visual Studio 2013

• Win32/Windows API & SDK

• MS Foundation Classes (MFC) & C++

• HTML, XAML

• C# vs. C++ concepts/differences

• Common Gateway Interface (CGI) programming

• The .Net Framework

• Windows Forms

• WPF - Windows Presentation Foundation Using DirectX + XAML & RTL (post-Vista)

• Android

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Paradigms

• 4 different ways to build a GUI program:

• Each has advantages/disadvantages

– WIN32API – lower-level control, works on older systems

– Microsoft Foundation Classes – many pre-built objects

– Windows Forms – presentation separated from processing

– Windows Presentation Foundation• Can build common browser-based and desktop apps

• Easier handling of media types

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Comparison of Paradigms

Win32API

MFCWindows

Forms

Windows Forms+APICodepack

WPF

GUI forms and controls

X X X X

On-screen documents

X X X

Fixed-format documents (PDF)

ext X X

Images BMP X

Video/audioUse

Media Player

X X

2D graphics " X X

3D graphics " X X

Note: WPF – see WindowsFormsHost control 4(c) D. Foreman 8/21/19

Basic Concepts for all GUI's

• "Control" – MS term for mechanisms that manage what appears on the screen

– Sliders, pointers, windows, data entry boxes, etc.

• Messages – system code indicating user action

• Message loop

– Mechanism to pass execution between system app

– Uses messages to determine processing

• Multi-threading O/S

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Fonts & Pixels

• Dots per inch (DPI)

• Device-independent pixel (DIPs) (1/96 of a logical inch)

• 1 pt = 1/72 inch (ALWAYS!!!)– 12pt font takes 12/72 inch in HEIGHT

– Some characters need more or less space (e.g.; letters L and I)

– A 72-point font is defined to be one logical inch tall = 96px

– 1 logical inch=96 pixels

– A 12pt font needs 12 points/(72 points per inch)=1/6 of an inch

– 12 points = 1/6 logical inch = 96/6 = 16 pixels

– BUT if display is set to 144 DPI, then 72pt font=144 px NOT 96• Because that inch now has to hold 144 pixels, not 72 or 96

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MS naming conventions

prefix data type---------------------------------by BYTE (unsigned char)b BOOL (int, TRUE=1 FALSE=0)c chardw DWORD (4-byte unsigned long)fn functionh handlel long (4 bytes)n short (int) near pointerp pointersz null-terminated char stringw word (two bytes)lpsz long ptr to null-terminated str

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Processing window messages

• Message codes for event triggering

• A "callback" mechanism (next slide)

– O/S calls your function

– Reverse of a "system call"

• Message processing loop in program

– Tests for message types

– Calls your handler functions

• Program is idle until an event

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Callback Functions

A thread-like mechanism:

1. Program issues a service call to O/S

a. Tells O/S address of callback fn

b. Tells O/S when to call it (msg filter)

2. Program loop waits for an "event" message

3. Program reads message from queue, tells O/S to signal the callback function, loops for more msgs, NO WAIT for msg processing

4. O/S starts callback fn to process the message

5. Callback returns to O/S

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Model-View-Controller (MVC) Architecture

• 3 parts of an application:

– Data, interface, operations

• MVC separates pgm data types from presentation

• Reduces complexities/dependencies

• Model

– application data specs

• View – what the user sees (may also be controller)

• Controller - code to process the data

– Accepts input

– Rules for processing

– Converts to pgm-usable data (codes, msgs, etc)

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Win32API Architecture

• Core set of system interfaces– Kernel32.dll

• Mem mgmt., I/O, process, thread

– User32.dll• implements abstractions for Windows apps

– HWND

– MSG

– Message loop

– Build, obscure, size, move, dialogs, etc

– GDI32.dll• Drawing lines & curves

• Manage palettes

• Rendering fonts

• Predecessor of DirectX/OpenGL

• No "frames", no rasterization, SLOW

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Win32 = Windows API

• Uses basic windows functions

• Usable with C/C++, Java

• Programmer must do almost everything

• Used with the Windows SDK (NOT MFC)

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MICROSOFT FOUNDATION CLASSES

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MFC architecture

• Based on Document/View concept

– Separation of data from the user's view of data

– Data is what user sees with "open a file"

• Operations

– Design the window(s) - these are the "views"

– Process the data based on user input

– Switch/modify windows as needed to show results

– E.g.; represent a collection of numbers as• Table

• Graph

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MS Foundation Classes (MFC)

• A C++ class library

• Builds on portions of the Win32API

• Pre-defined classes contain pre-written code:

– Independent of user settings• Create/Open/Close a window

• Open a dialog box

– Adjustable (size, content, etc.) via the program

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WINDOWS FORMS (WF)

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Windows Forms (WF) Architecture

• Use C# or Visual Basic

• GUI part of .NET Framework

• Does not offer a paradigm comparable to Model–View–Controller paradigm of MFC

• Event driven

• Feature of .NET Framework

• Usage:

– Design a form (e.g.; built-in wizard in MS Access, Visual Basic)

– Specify parts of program that process each part

– Function names to call are embedded in the form

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WINDOWS PRESENTATION FOUNDATION

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WPF Architecture

• Provides many h/w-related advances– Hardware acceleration (graphic adapter card)

also called Graphics Processing Unit (GPU)

– Enables modern UI features • transparency, gradients and transforms

• Deployable on desktop or web browser

• Subset of .Net Framework types – Mostly in System.Windows

– WPF provides additions for properties & routed events

• Uses markup & code-behind concepts– XAML

– Managed languages (C#)

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WPF (4.5 – Aug 2012 – might be the last version)

• 1st release in 2005

• Implements SOAP & non-MS web svc's tech's.

• DirectX vs. older GDI interface

• C#, .Net, XAML (based on XML)

• Standalone apps

• Embedded objects on a website

• RTL included in all Windows post-XP

• Unifies– Rendering, typography, vector graphics, animation, fixed,

adaptive & pre-rendered docs, events, bindings

• Poor response-time, not for low-power devices

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WPF vs. WinForms

• WPF

– Does not rely on "standard" windows controls

– A "window" is just a border around "content"

– e.g.; Can make a button with image & text in it

– BUT may take more work for "simple" things

• WF

– ONLY uses standard "windows"• Dialog/text boxes, etc.

– Button w/image would require you to create your own button control type

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WPF example – part 1

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="SDKSample.AWindow" Title="Window with Button"

Width="250" Height="100">

<!-- Add button to window -->

<Button Name="button" Click="button_Click">Click Me!

</Button>

</Window>

• x:Class associates

– XAML def'n of window (above)

– code-behind class (Awindow) on next slide

• This example (parts 1 & 2) is from:

http://msdn.microsoft.com/en-us/library/aa970268(v=vs.110).aspx

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WPF example –part 2

using System.Windows; // Window, RoutedEventArgs, MessageBox

namespace SDKSample

{ public partial class AWindow : Window

{ public AWindow()

{

// Set properties and register event handlers InitializeComponent(); // Required to merge this class & XAML

}

void button_Click(object sender, RoutedEventArgs e)

{ // Show message box when button is clicked MessageBox.Show("Hello, from WPF app!");

}

}

}

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.NET (3.0) stack

.NET Apps .NET Tools

CLR, Base Class Libraries, ASP.NET, ASO.NET, WinForms

WPF CardSpace(InfoCard)Canceled!

WF(Workflow)

Windows

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Deploying .NET Framework Apps

• Distinguish between the app and the Framework

• http://msdn.microsoft.com/en-us/library/6hbb4k3e(v=vs.110).aspx

• http://support.microsoft.com/kb/818016

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