第八章 计时器（DIGCLOCK）

  1 /*--------------------------------------
  2 DIGCLOCK.C -- Digital Clock
  3               (c) Charles Petzold, 1998
  4 --------------------------------------*/
  5 
  6 #include <Windows.h>
  7 
  8 #define ID_TIMER 1
  9 
 10 LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
 11 
 12 int WINAPI WinMain( __in HINSTANCE hInstance
 13                     , __in_opt HINSTANCE hPrevInstance
 14                     , __in LPSTR lpCmdLine
 15                     , __in int nShowCmd )
 16 {
 17     static TCHAR szAppName[] = TEXT("DigClock");
 18     HWND hwnd;
 19     MSG msg;
 20     WNDCLASS wndclass;
 21 
 22     wndclass.style = CS_HREDRAW | CS_VREDRAW;
 23     wndclass.lpfnWndProc = WndProc;
 24     wndclass.cbClsExtra = 0;
 25     wndclass.cbWndExtra = 0;
 26     wndclass.hInstance = hInstance;
 27     wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
 28     wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
 29     wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
 30     wndclass.lpszMenuName = NULL;
 31     wndclass.lpszClassName = szAppName;
 32 
 33     if (!RegisterClass(&wndclass))
 34     {
 35         MessageBox(NULL, TEXT("Program requires Windows NT!")
 36             , szAppName, MB_ICONERROR);
 37         return 0;
 38     }
 39 
 40     hwnd = CreateWindow(szAppName, TEXT("Digital Clock")
 41         , WS_OVERLAPPEDWINDOW
 42         , CW_USEDEFAULT, CW_USEDEFAULT
 43         , CW_USEDEFAULT, CW_USEDEFAULT
 44         , NULL, NULL, hInstance, NULL);
 45 
 46     ShowWindow(hwnd, nShowCmd);
 47     UpdateWindow(hwnd);
 48 
 49     while (GetMessage(&msg, NULL, 0, 0))
 50     {
 51         TranslateMessage(&msg);
 52         DispatchMessage(&msg);
 53     }
 54 
 55     return msg.wParam;
 56 }
 57 
 58 void DisplayDigit(HDC hdc, int iNumber)
 59 {
 60     static BOOL fSevenSegment[10][7] = 
 61     {
 62         1, 1, 1, 0, 1, 1, 1,    //0
 63         0, 0, 1, 0, 0, 1, 0,    //1
 64         1, 0, 1, 1, 1, 0, 1,    //2
 65         1, 0, 1, 1, 0, 1, 1,    //3
 66         0, 1, 1, 1, 0, 1, 0,    //4
 67         1, 1, 0, 1, 0, 1, 1,    //5
 68         1, 1, 0, 1, 1, 1, 1,    //6
 69         1, 0, 1, 0, 0, 1, 0,    //7
 70         1, 1, 1, 1, 1, 1, 1,    //8
 71         1, 1, 1, 1, 0, 1, 1        //9
 72     };
 73 
 74     static POINT ptSegment[7][6] =
 75     {
 76         7, 6, 11, 2, 31, 2, 35, 6, 31, 10, 11, 10,
 77         6, 7, 10, 11, 10, 31, 6, 35, 2, 31, 2, 11,
 78         36, 7, 40, 11, 40, 31, 36, 35, 32, 31, 32, 11,
 79         7, 36, 11, 32, 31, 32, 35, 36, 31, 40, 11, 40,
 80         6, 37, 10, 41, 10, 61, 6, 65, 2, 61, 2, 41,
 81         36, 37, 40, 41, 40, 61, 36, 65, 32, 61, 32, 41,
 82         7, 66, 11, 62, 31, 62, 35, 66, 31, 70, 11, 70 
 83 
 84     };
 85 
 86     for (int iSeg(0); iSeg != 7; ++iSeg)
 87     {
 88         if (fSevenSegment[iNumber][iSeg])
 89             Polygon(hdc, ptSegment[iSeg], 6);
 90     }
 91 }
 92 
 93 void DisplayTwoDigits(HDC hdc, int iNumber, BOOL fSuppress)
 94 {
 95     if (!fSuppress || (iNumber / 10 != 0))
 96         DisplayDigit(hdc, iNumber / 10);
 97     
 98     OffsetWindowOrgEx(hdc, -42, 0, NULL);
 99     DisplayDigit(hdc, iNumber % 10);
100     OffsetWindowOrgEx(hdc, -42, 0, NULL);
101 }
102 
103 void DisplayColon(HDC hdc)
104 {
105     POINT ptColon[2][4] = { 2, 21, 6, 17, 10, 21, 6, 25,
106                             2, 51, 6, 47, 10, 51, 6, 55 };
107     
108     Polygon(hdc, ptColon[0], 4);
109     Polygon(hdc, ptColon[1], 4);
110 
111     OffsetWindowOrgEx(hdc, -12, 0, NULL);
112 }
113 
114 void DisplayTime(HDC hdc, BOOL f24Hour, BOOL fSuppress)
115 {
116     SYSTEMTIME st;
117 
118     GetLocalTime(&st);
119 
120     if (f24Hour)
121         DisplayTwoDigits(hdc, st.wHour, fSuppress);
122     else
123         DisplayTwoDigits(hdc, (st.wHour %= 12) ? st.wHour : 12, fSuppress);
124 
125     DisplayColon(hdc);
126     DisplayTwoDigits(hdc, st.wMinute, FALSE);
127     DisplayColon(hdc);
128     DisplayTwoDigits(hdc, st.wSecond, FALSE);
129 }
130 
131 LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
132 {
133     static BOOL f24Hour, fSuppress;
134     static HBRUSH hBrushRed;
135     static int cxClient, cyClient;
136     HDC hdc;
137     PAINTSTRUCT ps;
138     TCHAR szBuffer[2];
139 
140     switch (message)
141     {
142     case WM_CREATE:
143         hBrushRed = CreateSolidBrush(RGB(255, 0, 0));
144         SetTimer(hwnd, ID_TIMER, 1000, NULL);
145 
146         //fall through
147     case WM_SETTINGCHANGE:
148         GetLocaleInfo(LOCALE_USER_DEFAULT, LOCALE_ITIME, szBuffer, 2);
149         f24Hour = (szBuffer[0] == TEXT(‘1‘));
150 
151         GetLocaleInfo(LOCALE_USER_DEFAULT, LOCALE_ITLZERO, szBuffer, 2);
152         fSuppress = (szBuffer[0] == TEXT(‘0‘));
153 
154         InvalidateRect(hwnd, NULL, TRUE);
155         return 0;
156 
157     case WM_SIZE:
158         cxClient = LOWORD(lParam);
159         cyClient = HIWORD(lParam);
160         return 0;
161 
162     case WM_TIMER:
163         InvalidateRect(hwnd, NULL, TRUE);
164         return 0;
165 
166     case WM_PAINT:
167         hdc = BeginPaint(hwnd, &ps);
168 
169         SetMapMode(hdc, MM_ISOTROPIC);
170         SetWindowExtEx(hdc, 276, 72, NULL);
171         SetViewportExtEx(hdc, cxClient, cyClient, NULL);
172 
173         SetWindowOrgEx(hdc, 138, 36, NULL);
174         SetViewportOrgEx(hdc, cxClient / 2, cyClient / 2, NULL);
175         SelectObject(hdc, GetStockObject(NULL_PEN));
176         SelectObject(hdc, hBrushRed);
177 
178         DisplayTime(hdc, f24Hour, fSuppress);
179 
180         EndPaint(hwnd, &ps);
181         return 0;
182 
183     case WM_DESTROY:
184         KillTimer(hwnd, ID_TIMER);
185         DeleteObject(hBrushRed);
186         PostQuitMessage(0);
187         return 0;
188     }
189 
190     return DefWindowProc(hwnd, message, wParam, lParam);
191 }