1
Win32 Programming Basic Concepts
Ping-Lun Liao
Outline
Windows Message
Resources
Samples Demo
Windows and Applications
Mechanisms to starts/terminate the application
Windows Application Components
Message Everywhere
Event-Driven
Message-Based Action
What is Windows Message?
System-Defined Message
Application-Defined Message
System-Defined Message
The system sends or posts a system-defined message when it
communicates with an application.
It uses these messages to control the operations of applications
and to provide input and other information for applications to
process.
System-Defined Message
An application can also send or post system-defined
messages.
Applications generally use these messages to control the
operation of control windows created by using preregistered window
classes.
System-Defined Message
Application-Defined Message
An application can create messages to be used by its own windows
or to communicate with windows in other processes.
If an application creates its own messages, the window procedure
that receives them must interpret the messages and provide
appropriate processing.
Steps For Creating A Window
Step 1: Registering the Window Class
Step 2: Creating the Window
Step 3: The Message Loop
Step 4: the Window Procedure
A Simple Window
A Simple Window
Message Handling
Message Loop
Window Procedure
The Message Loop
retrieves message from the message queue
sends message to the Windows procedure where the messages are
processed
loops back and repeats the procedure
The Message Loop
Programs generally don't call window procedures directly.
The window procedure is almost always called from Windows
itself.
A program can indirectly call its own window procedure by
calling a function named SendMessage().
The Message Loop
Messages come through in an orderly and synchronized manner.
While processing one message in a window procedure, the program
will not be suddenly interrupted by another message.
Message Handling
WM_LBUTTONDOWN
WM_DESTROY
WM_PAINT
WM_CREATE
The Message Loop
Message loop retrieves a message from its message queue
Call DispatchMessage() to send the message off to the window
procedure
DispatchMessage() does not return until the window procedure has
returned control back to Windows.
The Message Loop
Windows Class and Registration
Windows Dialog Box
Windows Application Lifecycle
Resources
Standard - icon, cursor, menu, dialog box, bitmap, enhanced
metafile, font, accelerator table, message-table entry,
string-table entry, or version
Custom - any kind of data that doesn't fall into the previous
category (for example a mp3 file or a dictionary database).
Three dynamic-link libraries
Kernel32.dll
File I/O, System,
User32.dll
User Interface
Gdi32.dll
Fonts, Brushes
First Windows Program
Win32 API
Win32ASM
Visual C++
MFC (Microsoft Foundation Classes)
BCB (Borland C++ Builder)
VCL (Visual Component Library)
VB(???)
.Net(C#, J#, C++, VB.NET)
Windows Form
Win32 API
Numeric identifiers
In header file (always called resource.h)
Example
#define IDMAINMENU 300
#define IDM_FILE_NEW 301
#define IDM_FILE_OPEN 302
#define IDM_FILE_SAVE 303
#define IDM_FILE_EXIT 304
#define IDM_HELP_ABOUT 305
Something about GetMessage
WarningBecause the return value can be nonzero, zero, or -1,
avoid code like this:
while (GetMessage( lpMsg, hWnd, 0, 0)) ...
Solution
BOOL bRet;while( (bRet = GetMessage( &msg, NULL, 0, 0 )) !=
0) { if (bRet == -1) { // handle the error and possibly exit } else
{ TranslateMessage(&msg); DispatchMessage(&msg); } }
Reference
MFC
theForger's Win32 API Programming Tutorial
Click to edit the title text format
Click to edit the outline text formatSecond Outline LevelThird
Outline LevelFourth Outline LevelFifth Outline LevelSixth Outline
LevelSeventh Outline Level
