《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);
 }