第八章 计时器（DIGCLOCK）

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

 DIGCLOCK.C -- Digital Clock

               (c) Charles Petzold, 1998

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

 #include <Windows.h>

 #define ID_TIMER 1

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

 int WINAPI WinMain( __in HINSTANCE hInstance

                     , __in_opt HINSTANCE hPrevInstance

                     , __in LPSTR lpCmdLine

                     , __in int nShowCmd )

 {

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

     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("Digital Clock")

         , 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;

 }

 void DisplayDigit(HDC hdc, int iNumber)

 {

     static BOOL fSevenSegment[][] =

     {

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         , , , , , , ,    //

         , , , , , , ,    //

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         , , , , , , ,    //

         , , , , , , ,    //

         , , , , , , ,    //

         , , , , , ,         //

     };

     static POINT ptSegment[][] =

     {

         , , , , , , , , , , , ,

         , , , , , , , , , , , ,

         , , , , , , , , , , , ,

         , , , , , , , , , , , ,

         , , , , , , , , , , , ,

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         , , , , , , , , , , ,

     };

     for (int iSeg(); iSeg != ; ++iSeg)

     {

         if (fSevenSegment[iNumber][iSeg])

             Polygon(hdc, ptSegment[iSeg], );

     }

 }

 void DisplayTwoDigits(HDC hdc, int iNumber, BOOL fSuppress)

 {

     if (!fSuppress || (iNumber /  != ))

         DisplayDigit(hdc, iNumber / );

     OffsetWindowOrgEx(hdc, -, , NULL);

     DisplayDigit(hdc, iNumber % );

     OffsetWindowOrgEx(hdc, -, , NULL);

 }

 void DisplayColon(HDC hdc)

 {

     POINT ptColon[][] = { , , , , , , , ,

                             , , , , , , ,  };

     Polygon(hdc, ptColon[], );

     Polygon(hdc, ptColon[], );

     OffsetWindowOrgEx(hdc, -, , NULL);

 }

 void DisplayTime(HDC hdc, BOOL f24Hour, BOOL fSuppress)

 {

     SYSTEMTIME st;

     GetLocalTime(&st);

     if (f24Hour)

         DisplayTwoDigits(hdc, st.wHour, fSuppress);

     else

         DisplayTwoDigits(hdc, (st.wHour %= ) ? st.wHour : , fSuppress);

     DisplayColon(hdc);

     DisplayTwoDigits(hdc, st.wMinute, FALSE);

     DisplayColon(hdc);

     DisplayTwoDigits(hdc, st.wSecond, FALSE);

 }

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

 {

     static BOOL f24Hour, fSuppress;

     static HBRUSH hBrushRed;

     static int cxClient, cyClient;

     HDC hdc;

     PAINTSTRUCT ps;

     TCHAR szBuffer[];

     switch (message)

     {

     case WM_CREATE:

         hBrushRed = CreateSolidBrush(RGB(, , ));

         SetTimer(hwnd, ID_TIMER, , NULL);

         //fall through

     case WM_SETTINGCHANGE:

         GetLocaleInfo(LOCALE_USER_DEFAULT, LOCALE_ITIME, szBuffer, );

         f24Hour = (szBuffer[] == TEXT(''));

         GetLocaleInfo(LOCALE_USER_DEFAULT, LOCALE_ITLZERO, szBuffer, );

         fSuppress = (szBuffer[] == TEXT(''));

         InvalidateRect(hwnd, NULL, TRUE);

         return ;

     case WM_SIZE:

         cxClient = LOWORD(lParam);

         cyClient = HIWORD(lParam);

         return ;

     case WM_TIMER:

         InvalidateRect(hwnd, NULL, TRUE);

         return ;

     case WM_PAINT:

         hdc = BeginPaint(hwnd, &ps);

         SetMapMode(hdc, MM_ISOTROPIC);

         SetWindowExtEx(hdc, , , NULL);

         SetViewportExtEx(hdc, cxClient, cyClient, NULL);

         SetWindowOrgEx(hdc, , , NULL);

         SetViewportOrgEx(hdc, cxClient / , cyClient / , NULL);

         SelectObject(hdc, GetStockObject(NULL_PEN));

         SelectObject(hdc, hBrushRed);

         DisplayTime(hdc, f24Hour, fSuppress);

         EndPaint(hwnd, &ps);

         return ;

     case WM_DESTROY:

         KillTimer(hwnd, ID_TIMER);

         DeleteObject(hBrushRed);

         PostQuitMessage();

         return ;

     }

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

 }

DIGCLOCK.C