第七章 鼠标（CONNECT）

  1 /*
  2 CONNECT.C -- Connect-the-Dots Mouse Demo Program
  3             (c) Charles Petzold,1998
  4 */
  5 
  6 #include <Windows.h>
  7 
  8 #define MAXPOINTS 1000
  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("Connect");
 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("Connect-the-Points Mouse Demo")
 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 LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 59 {
 60     static POINT pt[MAXPOINTS];
 61     static int iCount;
 62     HDC hdc;
 63     int i, j;
 64     PAINTSTRUCT ps;
 65 
 66     switch (message)
 67     {
 68     case WM_LBUTTONDOWN:
 69         iCount = 0;
 70         InvalidateRect(hwnd, NULL, TRUE);
 71         return 0;
 72 
 73     case WM_MOUSEMOVE:
 74         if (wParam & MK_LBUTTON && iCount < 1000)
 75         {
 76             pt[iCount  ].x = LOWORD(lParam);
 77             pt[iCount++].y = HIWORD(lParam);
 78             
 79             hdc = GetDC(hwnd);
 80             SetPixel(hdc, LOWORD(lParam), HIWORD(lParam), 0);
 81             ReleaseDC(hwnd, hdc);
 82         }
 83         return 0;
 84 
 85     case WM_LBUTTONUP:
 86         InvalidateRect(hwnd, NULL, FALSE);
 87         return 0;
 88 
 89     case WM_PAINT:
 90         hdc = BeginPaint(hwnd, &ps);
 91 
 92         SetCursor(LoadCursor(NULL, IDC_WAIT));
 93         ShowCursor(TRUE);
 94 
 95         for (i = 0; i < iCount - 1; ++i)
 96             for (j = i + 1; j < iCount; ++j)
 97             {
 98                 MoveToEx(hdc, pt[i].x, pt[i].y, NULL);
 99                 LineTo(hdc, pt[j].x, pt[j].y);
100             }
101 
102         ShowCursor(FALSE);
103         SetCursor(LoadCursor(NULL, IDC_ARROW));
104 
105         EndPaint(hwnd, &ps);
106         return 0;
107 
108     case WM_DESTROY:
109         PostQuitMessage(0);
110         return 0;
111     }
112 
113     return DefWindowProc(hwnd, message, wParam, lParam);
114 }