> chapter 8 beeper

最新推荐文章于 2024-12-26 10:35:51 发布

iteye_1315

最新推荐文章于 2024-12-26 10:35:51 发布

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本文提供了一个使用Windows API实现的简单应用程序示例，该程序利用定时器功能使窗口背景颜色在蓝色和红色间交替变化，并播放提示音。通过设置定时器，每隔1秒触发WM_TIMER消息，从而改变窗口背景颜色并发出声音。

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#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) ; //sound fFlipFlop = !fFlipFlop ;//~ InvalidateRect (hwnd, NULL, FALSE) ;//sent WM_PAINT 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) ; }