用键盘模拟鼠标

<<Windows程序设计>> Charles Petzold

P237

//CHECKER2.C

/*-------------------------------------------------
   CHECKER2.C -- Mouse Hit-Test Demo Program No. 2
                 (c) Charles Petzold, 1998
  -------------------------------------------------*/

#include <windows.h>

#define DIVISIONS 5

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

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     static TCHAR szAppName[] = TEXT ("Checker2") ;
     HWND         hwnd ;
     MSG          msg ;
     WNDCLASS     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 ;
     
     if (!RegisterClass (&wndclass))
     {
          MessageBox (NULL, TEXT ("Program requires Windows NT!"), 
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }
     hwnd = CreateWindow (szAppName, TEXT ("Checker2 Mouse Hit-Test 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 message, WPARAM wParam, LPARAM lParam)
{
     static BOOL fState[DIVISIONS][DIVISIONS] ;
     static int  cxBlock, cyBlock ;
     HDC         hdc ;
     int         x, y ;
     PAINTSTRUCT ps ;
     POINT       point ;
     RECT        rect ;
     
     switch (message)
     {
     case WM_SIZE :
          cxBlock = LOWORD (lParam) / DIVISIONS ;
          cyBlock = HIWORD (lParam) / DIVISIONS ;
          return 0 ;
          
     case WM_SETFOCUS :

		  //显示鼠标:只要display count是非负,windows就会显示鼠标,即使没有安装鼠标也会显示.
		 // 如果没有安装鼠标,display count 的初始值是-1,如果安装了,初始值是0
		 //因此不管是否安装了鼠标,只要调用 ShowCursor (TRUE)就能在屏幕上显示鼠标箭头
		 
          ShowCursor (TRUE); //这个函数的作用是使得display count 加1,也就是能显示鼠标了.		 
          return 0 ;
          
     case WM_KILLFOCUS :

          ShowCursor (FALSE) ;//display count  = -1; 不显示鼠标
          return 0 ;
          
     case WM_KEYDOWN : //捕获到键盘按下的消息

		 // 不管有没有安装鼠标,只有是能把鼠标显示出来---通过调用 ShowCursor (TRUE)来显示鼠标箭头
		 //  就可以用  GetCursorPos 来获取鼠标箭头的屏幕坐标
		 // 这个函数 GetCursorPos()没有窗口句柄hwnd,所以肯定是屏幕坐标而不是窗口客户区坐标

          GetCursorPos (&point) ; 

          ScreenToClient (hwnd, &point) ;//把屏幕坐标转换成窗口客户区坐标

		  // point已经是客户区坐标了,因此x,y就是客户区的方块的位置
          x = max (0, min (DIVISIONS - 1, point.x / cxBlock)) ;
          y = max (0, min (DIVISIONS - 1, point.y / cyBlock)) ;
          
          switch (wParam)// 记住:在WM_KEYDOWN消息中,wParam参数保存的是虚拟键盘码
          {
          case VK_UP :
               y-- ;
               break ;
               
          case VK_DOWN :
               y++ ;
               break ;
               
          case VK_LEFT :
               x-- ;
               break ;
               
          case VK_RIGHT :
               x++ ;
               break ;
               
          case VK_HOME : //鼠标回到左上角的方块
               x = y = 0 ;
               break ;
               
          case VK_END : // 鼠标回到右下角的方块
               x = y = DIVISIONS - 1 ;
               break ;
               
          case VK_RETURN : //回车键
          case VK_SPACE :  //空格键
             /*
			  char str[20];
			  itoa(MK_LBUTTON,str,10);
			  MessageBox(hwnd, str, "按键MK_LBUTTON的值是?", MB_ICONINFORMATION);
			  */

			  //用回车键和空格键模拟鼠标左键按下
			  // 如果按下下回车键或者空格键就向窗口hwnd发送WM_LBUTTONDOWN消息
			  // MK_LBUTTON :表示鼠标左键按下
			  // MK_LBUTTON : Set if the left mouse button is down. 如果鼠标左键按下就Set,Set什么?
			  //  MK_LBUTTON, which is 0x0001 它的值是1
			  //  SendMessage(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam ),所以MK_LBUTTON就是当作wParam传入
			  // WPARAM实质是UINT 无符号整形
               SendMessage (hwnd, WM_LBUTTONDOWN, MK_LBUTTON,
                            MAKELONG (x * cxBlock, y * cyBlock)) ;
			   /* 经过测试表明 MK_LBUTTON的值是1
			   char str[20];
			   itoa(MK_LBUTTON,str,10);
			    MessageBox(hwnd, str, "按键MK_LBUTTON的值是?", MB_ICONINFORMATION);
				*/

               break ;
          }
          x = (x + DIVISIONS) % DIVISIONS ;
          y = (y + DIVISIONS) % DIVISIONS ;
          
          point.x = x * cxBlock + cxBlock / 2 ;
          point.y = y * cyBlock + cyBlock / 2 ;
          //把point转换为屏幕坐标上的点
          ClientToScreen (hwnd, &point) ;
		  //把鼠标设置为屏幕坐标上的点
          SetCursorPos (point.x, point.y) ;
          return 0 ;

     case WM_LBUTTONDOWN :
          x = LOWORD (lParam) / cxBlock ;
          y = HIWORD (lParam) / cyBlock ;
          
          if (x < DIVISIONS && y < DIVISIONS)
          {
               fState[x][y] ^= 1 ;
               
               rect.left   = x * cxBlock ;
               rect.top    = y * cyBlock ;
               rect.right  = (x + 1) * cxBlock ;
               rect.bottom = (y + 1) * cyBlock ;
               
               InvalidateRect (hwnd, &rect, FALSE) ;
          }
          else
               MessageBeep (0) ;
          return 0 ;
          
     case WM_PAINT :
          hdc = BeginPaint (hwnd, &ps) ;
          
          for (x = 0 ; x < DIVISIONS ; x++)
          for (y = 0 ; y < DIVISIONS ; y++)
          {
               Rectangle (hdc, x * cxBlock, y * cyBlock,
                          (x + 1) * cxBlock, (y + 1) * cyBlock) ;
                    
               if (fState [x][y])
               {
                    MoveToEx (hdc,  x   *cxBlock,  y   *cyBlock, NULL) ;
                    LineTo   (hdc, (x+1)*cxBlock, (y+1)*cyBlock) ;
                    MoveToEx (hdc,  x   *cxBlock, (y+1)*cyBlock, NULL) ;
                    LineTo   (hdc, (x+1)*cxBlock,  y   *cyBlock) ;
               }
          }
          EndPaint (hwnd, &ps) ;
          return 0 ;
               
     case WM_DESTROY :
          PostQuitMessage (0) ;
          return 0 ;
     }
     return DefWindowProc (hwnd, message, wParam, lParam) ;
}