使用计时器-方法1

Windows将WM_TIMER消息发送到应用程序的窗口过程。相应SetTimer的调用方法：

SetTimer(hwnd,1,uiMsecInterval,NULL);

在任何时刻停止WM_TIMER消息，方法如下：

KillTimer(hwnd,1);

当窗口收到WM_TIMER消息时，wParam等于计时器的ID，所以可以用如下方式：

#define TIMER_SEC 1

#define TIMER_MIN 2

    

SetTimer(hwnd,TIMER_SEC,1000,NULL);

SetTimer(hwnd,TIMER_MIN,60000,NULL);



case WM_TIMER:

    switch(wParam)

    {

          case : TIMER_SEC:

          case : TIMER_MIN:

    }

        

源代码如下：

/*-----------------------------------------

   BEEPER1.C  -- Timer Demo Program No. 1

                 (c) Charles Petzold, 1998

  -----------------------------------------*/

 

#include <windows.h>



#define ID_TIMER    1



LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;



int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,

                    PSTR szCmdLine, int iCmdShow)

{

     static TCHAR szAppName[] = TEXT ("Beeper1") ;

     HWND         hwnd ;

     MSG          msg ;

     WNDCLASS     wndclass ;

     

     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;

     wndclass.lpfnWndProc   = WndProc ;

     wndclass.cbClsExtra    = 0 ;

     wndclass.cbWndExtra    = 0 ;

     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 ("Program requires Windows NT!"), 

                      szAppName, MB_ICONERROR) ;

          return 0 ;

     }

     

     hwnd = CreateWindow (szAppName, TEXT ("Beeper1 Timer Demo"),

                          WS_OVERLAPPEDWINDOW,

                          CW_USEDEFAULT, CW_USEDEFAULT,

                          CW_USEDEFAULT, CW_USEDEFAULT,

                          NULL, NULL, hInstance, NULL) ;

          

     ShowWindow (hwnd, iCmdShow) ;

     UpdateWindow (hwnd) ;

          

     while (GetMessage (&msg, NULL, 0, 0))

     {

          TranslateMessage (&msg) ;

          DispatchMessage (&msg) ;

     }

     return msg.wParam ;

}



LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)

{

     static BOOL fFlipFlop = FALSE ;

     HBRUSH      hBrush ;

     HDC         hdc ;

     PAINTSTRUCT ps ;

     RECT        rc ;

     

     switch (message)

     {

     case WM_CREATE:

          SetTimer (hwnd, ID_TIMER, 1000, NULL) ;

          return 0 ;



     case WM_TIMER :

          MessageBeep (-1) ;          

          fFlipFlop = !fFlipFlop ;

          InvalidateRect (hwnd, NULL, FALSE) ;

          return 0 ;

          

     case WM_PAINT :

          hdc = BeginPaint (hwnd, &ps) ;

          

          GetClientRect (hwnd, &rc) ;

          hBrush = CreateSolidBrush (fFlipFlop ? RGB(255,0,0) : RGB(0,0,255)) ;

          FillRect (hdc, &rc, hBrush) ;



          EndPaint (hwnd, &ps) ;

          DeleteObject (hBrush) ;

          return 0 ;

          

     case WM_DESTROY :

          KillTimer (hwnd, ID_TIMER) ;

          PostQuitMessage (0) ;

          return 0 ;

     }

     return DefWindowProc (hwnd, message, wParam, lParam) ;

}

执行结果：

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