第八章 计时器（BEEPER2）

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

 BEEPER2.C -- Timer Demo Program No.1

              (c) Charles Petzold, 1998

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

 #include <Windows.h>

 #define ID_TIMER 1

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

 VOID CALLBACK TimerPorc(HWND, UINT, UINT, DWORD);

 int WINAPI WinMain( __in HINSTANCE hInstance

                     , __in_opt HINSTANCE hPrevInstance

                     , __in LPSTR lpCmdLine

                     , __in int nShowCmd )

 {

     static TCHAR szAppName[] = TEXT("Bepper2");

     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("Program requires Windows NT!")

             , szAppName, MB_ICONERROR);

         return ;

     }

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

         , WS_OVERLAPPEDWINDOW

         , CW_USEDEFAULT, CW_USEDEFAULT

         , CW_USEDEFAULT, CW_USEDEFAULT

         , NULL, NULL, hInstance, NULL);

     ShowWindow(hwnd, nShowCmd);

     UpdateWindow(hwnd);

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

     {

         TranslateMessage(&msg);

         DispatchMessage(&msg);

     }

     return msg.wParam;

 }

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

 {

     switch (message)

     {

     case WM_CREATE:

         SetTimer(hwnd, ID_TIMER, , TimerPorc);

         return ;

     case WM_DESTROY:

         KillTimer(hwnd, ID_TIMER);

         PostQuitMessage();

         return ;

     }

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

 }

 VOID CALLBACK TimerPorc(HWND hwnd, UINT message, UINT iTimerID, DWORD dwTime)

 {

     static BOOL fFlipFlop = FALSE;

     HBRUSH hBrush;

     HDC hdc;

     RECT rc;

     MessageBeep(-);

     fFlipFlop = !fFlipFlop;

     GetClientRect(hwnd, &rc);

     hdc = GetDC(hwnd);

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

     FillRect(hdc, &rc, hBrush);

     ReleaseDC(hwnd, hdc);

     DeleteObject(hBrush);

 }

BEEPER2.C