《windows程序设计》学习_2.1：初识消息

 #include <windows.h>
 
 //#define WM_MYMSG (WM_USER +100)
 
 LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);    
 
 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
 {
     static TCHAR szAppName[] = TEXT ("HelloWin");
     HWND         hwnd;
     MSG          msg;
     WNDCLASS     wndclass;
 
     wndclass.style              = CS_HREDRAW | CS_VREDRAW  ;
     wndclass.lpfnWndProc        = WndProc ;
     wndclass.cbClsExtra         =  ;
     wndclass.cbWndExtra         =  ;
     wndclass.hInstance          = hInstance ;
     wndclass.hIcon              = LoadIcon(NULL,IDI_APPLICATION) ;
     wndclass.hCursor            = LoadCursor(NULL,IDC_ARROW) ;
     wndclass.hbrBackground      = (HBRUSH) GetStockObject(WHITE_BRUSH) ;
     wndclass.lpszMenuName       = NULL ;
     wndclass.lpszClassName      = szAppName ;
 
     if(!RegisterClass(&wndclass))
     {
         MessageBox(NULL, TEXT("This program requires Windows NT!"),
             szAppName, MB_ICONERROR);
 
         return ;
     }
 
     hwnd = CreateWindow(szAppName,
         TEXT("The Hello Program"),
         WS_OVERLAPPEDWINDOW,
         CW_USEDEFAULT,
         CW_USEDEFAULT,
         CW_USEDEFAULT,
         CW_USEDEFAULT,
         NULL,
         NULL,
         hInstance,
         NULL);
 
     ShowWindow(hwnd , iCmdShow);
     UpdateWindow(hwnd);
 
     while(GetMessage (&msg, NULL, , ))
     {
         TranslateMessage(&msg);
         DispatchMessage(&msg);
     }
 
     return msg.wParam;
 }
 
 LRESULT CALLBACK WndProc(HWND hwnd , UINT message , WPARAM wParam , LPARAM lParam)
 {
     HDC         hdc;
     PAINTSTRUCT ps;
     RECT        rect;
 
     switch(message)
     {
     case WM_CREATE:
 //        PlaySound (TEXT ("123.wav"), NULL , SND_FILENAME |SND_ASYNC);
         return ;
 
     case WM_PAINT:
         hdc = BeginPaint(hwnd , &ps);
 
         GetClientRect(hwnd, &rect);
 
         DrawText(hdc , TEXT("Hello Windows 98!") , - ,&rect ,
             DT_SINGLELINE | DT_CENTER | DT_VCENTER);
 
         EndPaint(hwnd,&ps);
 
 //        PlaySound (TEXT ("123.wav"), NULL , SND_FILENAME |SND_ASYNC);
         return ;
 /*
     case WM_MYMSG:
         PlaySound (TEXT ("123.wav"), NULL , SND_FILENAME |SND_ASYNC);
         return 0;                                                          //自定义消息
 */
     case WM_LBUTTONDOWN:
 //        PlaySound (TEXT ("123.wav"), NULL , SND_FILENAME |SND_ASYNC);
 //        InvalidateRect(hwnd, NULL , FALSE);
 //        SendMessage(hwnd , WM_MYMSG , wParam , lParam);
         return ;
 
     case WM_DESTROY:
 //        PlaySound (TEXT ("123.wav"), NULL , SND_FILENAME |SND_ASYNC);
         PostQuitMessage();
         return ;
     }
     return DefWindowProc(hwnd,message,wParam,lParam);
 }