GDI/图象编程

开发平台：
Visual C++

DEMO1_4.C：源码内容
							  1 /****************************************************************/
  2 /*         Demo1_4   ---  The simple example                    */
  3 /****************************************************************/
  4 
  5 #include <windows.h>
  6 #include "demo1_4.h"
  7 
  8 #define MAXPOINTS       30
  9 #define MaxX          1000
 10 #define MaxY          1000
 11 
 12 int  PASCAL  WinMain(HANDLE, HANDLE, LPSTR, int);
 13 long FAR PASCAL MainWndProc(HWND, unsigned, WORD, LONG);
 14 
 15 
 16 
 17 /****************************************************************/
 18 /*                      WinMain()                               */
 19 /****************************************************************/
 20 
 21 int PASCAL WinMain(HANDLE hInstance, HANDLE hPrevInstance,
 22                    LPSTR lpszCmdLine, int nCmdShow)
 23 {
 24    WNDCLASS wclass;
 25    MSG      msg;
 26    HWND     hWnd;
 27    char     szName[] = "Demo1_4";
 28 
 29    if (!hPrevInstance)
 30     {
 31         wclass.style         = CS_HREDRAW | CS_VREDRAW;
 32         wclass.lpfnWndProc   = MainWndProc;
 33         wclass.cbClsExtra    = 0;
 34         wclass.cbWndExtra    = 0;
 35         wclass.hInstance     = hInstance;
 36         wclass.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
 37         wclass.hCursor       = LoadCursor(NULL, IDC_ARROW);
 38         wclass.hbrBackground = GetStockObject(WHITE_BRUSH);
 39         wclass.lpszMenuName  = szName;
 40         wclass.lpszClassName = szName;
 41 
 42         if (!RegisterClass (&wclass))
 43            return (FALSE);
 44     }
 45 
 46     hWnd = CreateWindow(
 47                 szName,
 48                 "The simple example - V.3",
 49                 WS_OVERLAPPEDWINDOW | WS_VSCROLL | WS_HSCROLL,
 50                 CW_USEDEFAULT,
 51                 CW_USEDEFAULT,
 52                 CW_USEDEFAULT,
 53                 CW_USEDEFAULT,
 54                 NULL,
 55                 NULL,
 56                 hInstance,
 57                 NULL );
 58 
 59     if (!hWnd)
 60         return (FALSE);
 61 
 62     ShowWindow(hWnd, nCmdShow);
 63     UpdateWindow(hWnd);
 64 
 65     while (GetMessage(&msg, NULL, NULL,NULL))
 66        {
 67            TranslateMessage(&msg);
 68            DispatchMessage(&msg);
 69        }
 70     return (msg.wParam);
 71 }
 72 
 73 
 74 
 75 /****************************************************************/
 76 /*                      MainWndProc()                           */
 77 /****************************************************************/
 78 
 79 typedef struct tagSHAPE {
 80            int  x1, y1;
 81            int  x2, y2;
 82            int  ShapeID;
 83 } SHAPE;
 84 
 85 long FAR PASCAL MainWndProc(HWND hWnd, unsigned message,
 86                             WORD wParam, LONG lParam)
 87 {
 88    PAINTSTRUCT   ps;
 89    HDC           hDC;
 90    HMENU         hMenu;
 91    static int    ShapeID = IDM_LINE;
 92    RECT          Rect, dstRect;
 93    int           x1, x2, y1, y2;
 94    static int    CX, CY;
 95    int           i, Temp;
 96    static int    Num = 0;
 97    static SHAPE  Shape[MAXPOINTS];
 98    static int    OX, OY;
 99 
100    switch (message)
101     {
102         case WM_CREATE :
103                 srand(LOWORD(GetCurrentTime()));
104                 break;
105 
106         case WM_COMMAND :
107                 switch(wParam)
108                   {
109                     case IDM_CLEAR :
110                          Num = 0;
111                          InvalidateRect(hWnd, NULL, TRUE);
112                          UpdateWindow(hWnd);
113                          break;
114 
115                     case IDM_EXIT :
116                          DestroyWindow (hWnd);
117                          break;
118 
119                     case IDM_LINE :
120                          if (ShapeID != IDM_LINE)
121                            {
122                              hMenu = GetMenu(hWnd);
123                              CheckMenuItem(hMenu, ShapeID,
124                                                   MF_UNCHECKED);
125                              ShapeID = IDM_LINE;
126                              CheckMenuItem(hMenu, ShapeID,
127                                                   MF_CHECKED);
128                            }
129                          break;
130 
131                     case IDM_RECT :
132                          if (ShapeID != IDM_RECT)
133                            {
134                              hMenu = GetMenu(hWnd);
135                              CheckMenuItem(hMenu, ShapeID,
136                                                   MF_UNCHECKED);
137                              ShapeID = IDM_RECT;
138                              CheckMenuItem(hMenu, ShapeID,
139                                                   MF_CHECKED);
140                            }
141                          break;
142 
143                     case IDM_ELLIP :
144                          if (ShapeID != IDM_ELLIP)
145                            {
146                              hMenu = GetMenu(hWnd);
147                              CheckMenuItem(hMenu, ShapeID,
148                                                   MF_UNCHECKED);
149                              ShapeID = IDM_ELLIP;
150                              CheckMenuItem(hMenu, ShapeID,
151                                                   MF_CHECKED);
152                            }
153                          break;
154 
155                     case IDM_DRAW :
156                          if (Num == MAXPOINTS)
157                            {
158                               MessageBox(hWnd,
159                                 "Memory not enough", "Warning",
160                                 MB_OK | MB_ICONEXCLAMATION);
161                               break;
162                            }
163 
164                          hDC = GetDC(hWnd);
165 
166                          x1 = rand() % CX;
167                          y1 = rand() % CY;
168                          x2 = rand() % CX;
169                          y2 = rand() % CY;
170 
171                          switch (ShapeID)
172                            {
173                             case IDM_LINE :
174                                  MoveTo(hDC, x1, y1);
175                                  LineTo(hDC, x2, y2);
176                                  break;
177 
178                             case IDM_RECT :
179                                  Rectangle(hDC, x1, y1, x2, y2);
180                                  break;
181 
182                             case IDM_ELLIP :
183                                  Ellipse(hDC, x1, y1, x2, y2);
184                                  break;
185                            }
186 
187                          ReleaseDC(hWnd, hDC);
188 
189                          Shape[Num].x1 = OX + x1;
190                          Shape[Num].y1 = OY + y1;
191                          Shape[Num].x2 = OX + x2;
192                          Shape[Num].y2 = OY + y2;
193                          Shape[Num].ShapeID = ShapeID;
194                          Num ++;
195                          break;
196                   }
197                 break;
198 
199       case WM_PAINT :
200             hDC = BeginPaint(hWnd, &ps);
201             for (i=0; i<Num; i++)
202               {
203                 Rect.left  = min(Shape[i].x1-OX, Shape[i].x2-OX);
204                 Rect.right = max(Shape[i].x1-OX, Shape[i].x2-OX);
205                 Rect.top   = min(Shape[i].y1-OY, Shape[i].y2-OY);
206                 Rect.bottom= max(Shape[i].y1-OY, Shape[i].y2-OY);
207                 IntersectRect(&dstRect, &Rect, &(ps.rcPaint));
208                 if (IsRectEmpty(&dstRect))
209                     continue;
210 
211                 switch (Shape[i].ShapeID)
212                  {
213                    case IDM_LINE :
214                      MoveTo(hDC, Shape[i].x1-OX, Shape[i].y1-OY);
215                      LineTo(hDC, Shape[i].x2-OX, Shape[i].y2-OY);
216                      break;
217 
218                    case IDM_RECT :
219                      Rectangle(hDC, Shape[i].x1-OX, Shape[i].y1-OY,
220                                     Shape[i].x2-OX, Shape[i].y2-OY);
221                      break;
222 
223                    case IDM_ELLIP :
224                      Ellipse(hDC, Shape[i].x1-OX, Shape[i].y1-OY,
225                                   Shape[i].x2-OX, Shape[i].y2-OY);
226                      break;
227                  }
228               }
229             EndPaint(hWnd, &ps);
230             break;
231 
232       case WM_SIZE :
233                 GetClientRect(hWnd, &Rect);
234                 CX = Rect.right  - Rect.left;
235                 CY = Rect.bottom - Rect.top;
236                 SetScrollRange(hWnd, SB_HORZ, 0, MaxX-CX, TRUE);
237                 SetScrollRange(hWnd, SB_VERT, 0, MaxY-CY, TRUE);
238                 OX = min(OX, MaxX-CX);
239                 OY = min(OY, MaxY-CY);
240                 SetScrollPos(hWnd, SB_HORZ, OX, TRUE);
241                 SetScrollPos(hWnd, SB_VERT, OY, TRUE);
242                 break;
243 
244       case WM_KEYDOWN :
245                 switch (wParam)
246                   {
247                     case VK_HOME :
248                         SendMessage(hWnd, WM_HSCROLL,
249                                     SB_TOP, 0L);
250                         break;
251 
252                     case VK_END :
253                         SendMessage(hWnd, WM_HSCROLL,
254                                     SB_BOTTOM, 0L);
255                         break;
256 
257                     case VK_PRIOR :
258                         SendMessage(hWnd, WM_VSCROLL,
259                                     SB_TOP, 0L);
260                         break;
261 
262                     case VK_NEXT :
263                         SendMessage(hWnd, WM_VSCROLL,
264                                     SB_BOTTOM, 0L);
265                         break;
266 
267                     case VK_LEFT :
268                         SendMessage(hWnd, WM_HSCROLL,
269                                     SB_LINEUP, 0L);
270                         break;
271 
272                     case VK_RIGHT :
273                         SendMessage(hWnd, WM_HSCROLL,
274                                     SB_LINEDOWN, 0L);
275                         break;
276 
277                     case VK_UP :
278                         SendMessage(hWnd, WM_VSCROLL,
279                                     SB_LINEUP, 0L);
280                         break;
281 
282                     case VK_DOWN :
283                         SendMessage(hWnd, WM_VSCROLL,
284                                     SB_LINEDOWN, 0L);
285                         break;
286                   }
287                 break;
288 
289       case WM_HSCROLL :
290                 switch (wParam)
291                   {
292                     case SB_TOP :
293                         Temp = 0;
294                         break;
295 
296                     case SB_BOTTOM :
297                         Temp = MaxX - CX;
298                         break;
299 
300                     case SB_LINEUP :
301                     case SB_PAGEUP :
302                         Temp = OX - CX/4;
303                         break;
304 
305                     case SB_LINEDOWN :
306                     case SB_PAGEDOWN :
307                         Temp = OX + CX/4;
308                         break;
309 
310                     case SB_THUMBPOSITION :
311                         Temp = LOWORD(lParam);
312                         break;
313 
314                     default :
315                         return (NULL);
316                   }
317                 Temp = min(max(0, Temp), MaxX-CX);
318                 if (Temp == OX) break;
319 
320                 OX = Temp;
321                 SetScrollPos(hWnd, SB_HORZ, OX, TRUE);
322                 InvalidateRect(hWnd, NULL, TRUE);
323                 break;
324 
325       case WM_VSCROLL :
326                 switch (wParam)
327                   {
328                     case SB_TOP :
329                         Temp = 0;
330                         break;
331 
332                     case SB_BOTTOM :
333                         Temp = MaxY - CY;
334                         break;
335 
336                     case SB_LINEUP :
337                     case SB_PAGEUP :
338                         Temp = OY - CY/4;
339                         break;
340 
341                     case SB_LINEDOWN :
342                     case SB_PAGEDOWN :
343                         Temp = OY + CY/4;
344                         break;
345 
346                     case SB_THUMBPOSITION :
347                         Temp = LOWORD(lParam);
348                         break;
349 
350                     default :
351                         return (NULL);
352                   }
353                 Temp = min(max(0, Temp), MaxY-CY);
354                 if (Temp == OY) break;
355 
356                 OY = Temp;
357                 SetScrollPos(hWnd, SB_VERT, OY, TRUE);
358                 InvalidateRect(hWnd, NULL, TRUE);
359                 break;
360 
361       case WM_DESTROY :
362                 PostQuitMessage(0);
363                 break ;
364 
365       default :
366                 return (DefWindowProc(hWnd, message, wParam, lParam));
367     }
368    return (NULL);
369 }

						