connect.c

Programming Windows 程序开发设计指南

/*--------------------------------------------------
   CONNECT.C -- Connect-the-Dots Mouse Demo Program
                (c) Charles Petzold, 1996
  --------------------------------------------------*/

#include <windows.h>

#define MAXPOINTS 1000
#define MoveTo(hdc, x, y) MoveToEx (hdc, x, y, NULL)

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

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
     {
     static char szAppName[] = "Connect" ;
     HWND        hwnd ;
     MSG         msg ;
     WNDCLASSEX  wndclass ;

	 wndclass.cbSize        = sizeof (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 ;
	 wndclass.hIconSm       = LoadIcon (NULL, IDI_APPLICATION) ;

     RegisterClassEx (&wndclass) ;

     hwnd = CreateWindow (szAppName, "Connect-the-Points Mouse 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 iMsg, WPARAM wParam, LPARAM lParam)
     {
     static POINT points[MAXPOINTS] ;
     static int   iCount ;
     HDC          hdc ;
     PAINTSTRUCT  ps ;
     int          i, j ;

     switch (iMsg)
          {
          case WM_LBUTTONDOWN :
               iCount = 0 ;
               InvalidateRect (hwnd, NULL, TRUE) ;
               return 0 ;

          case WM_MOUSEMOVE :
               if (wParam & MK_LBUTTON && iCount < 1000)
                    {
                    points[iCount  ].x = LOWORD (lParam) ;
                    points[iCount++].y = HIWORD (lParam) ;

                    hdc = GetDC (hwnd) ;
                    SetPixel (hdc, LOWORD (lParam), HIWORD (lParam), 0L) ;
                    ReleaseDC (hwnd, hdc) ;
                    }
               return 0 ;

          case WM_LBUTTONUP :
               InvalidateRect (hwnd, NULL, FALSE) ;
               return 0 ;

          case WM_PAINT :
               hdc = BeginPaint (hwnd, &ps) ;

               SetCursor (LoadCursor (NULL, IDC_WAIT)) ;
               ShowCursor (TRUE) ;

               for (i = 0 ; i < iCount - 1 ; i++)
                    for (j = i + 1 ; j < iCount ; j++)
                         {
                         MoveTo (hdc, points[i].x, points[i].y) ;
                         LineTo (hdc, points[j].x, points[j].y) ;
                         }

               ShowCursor (FALSE) ;
               SetCursor (LoadCursor (NULL, IDC_ARROW)) ;

               EndPaint (hwnd, &ps) ;
               return 0 ;

          case WM_DESTROY :
               PostQuitMessage (0) ;
               return 0 ;
          }
     return DefWindowProc (hwnd, iMsg, wParam, lParam) ;
     }