抓鼠标的猫（Win32实现，Codeblocks+GCC编译）

程序效果：

猫的眼睛一直跟着鼠标移动：

鼠标经过猫的右脚附近时，猫会抓住鼠标。（未使用Hook）

代码：

//main.cpp
  1 #include <windows.h>
 #include <math.h>
 //#include <iostream>
 //using namespace std;
 LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
 double WIDTH=,HEIGHT=;
 double px=0.0,py=0.0;
 double ppx=0.0,ppy=0.0;
 POINT sp;
 int cat=;
 double width,height;
 PAINTSTRUCT ps ;
 RECT rect ;
 POINT pts[];
 double left_eye_px=0.0,right_eye_px=0.0;
 double eye_py=0.0;
 double eye_r=0.0;
 double k=0.0;
 double ball_hr=0.0;//半径
 double deltax=0.0;
 POINT p,pp;
 int initGraph=;
 LPPOINT catp;
 RECT eye_rect;
 HBRUSH  gray_brush =CreateSolidBrush (RGB(,,));
 HBRUSH  white_brush =CreateSolidBrush (RGB(,,));
 HBRUSH  black_brush =CreateSolidBrush (RGB(,,));
 int drawRound(HDC hdc,int x,int y,int r)    //r 直径
 {
     Ellipse(hdc,x-r/,y-r/,x+r/,y+r/);
     return ;
 }
 int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                     PSTR szCmdLine, int iCmdShow)
 {
     static TCHAR szAppName[] = TEXT ("HelloWin") ;
     HWND         hwnd ;
     MSG          msg ;
     WNDCLASS     wndclass ;
     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = WndProc ;
     wndclass.cbClsExtra    =  ;
     wndclass.cbWndExtra    =  ;
     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 ("This program requires Windows NT!"),
                     szAppName, MB_ICONERROR) ;
         return  ;
     }
     hwnd = CreateWindow (szAppName,                  // window class name
                          TEXT ("Mouse Hook"), // window caption
                          WS_OVERLAPPEDWINDOW,        // window style
                          CW_USEDEFAULT,              // initial x position
                          CW_USEDEFAULT,              // initial y position
                          WIDTH,              // initial x size
                          HEIGHT,              // initial y size
                          NULL,                       // parent window handle
                          NULL,                       // window menu handle
                          hInstance,                  // program instance handle
                          NULL) ;                     // creation parameters
     ShowWindow (hwnd, iCmdShow) ;
     UpdateWindow (hwnd) ;
     while (GetMessage (&msg, NULL, , ))
     {
         TranslateMessage (&msg) ;
         DispatchMessage (&msg) ;
     }
     return msg.wParam ;
 }

 int init(HWND hwnd)
 {
     GetClientRect (hwnd, &rect) ;
     width=rect.right-rect.left ;
     height=rect.bottom-rect.top ;
     left_eye_px=width*/-height/;
     right_eye_px=width*/+height/;
     eye_py=height*/-height/;
     eye_r=height/;
     ball_hr=eye_r/;//半径
     px=left_eye_px;
     py=eye_py;
     ppx=right_eye_px;
     ppy=eye_py;
     eye_rect.left=left_eye_px-eye_r/;
     eye_rect.right=right_eye_px+eye_r/;
     eye_rect.top=eye_py-eye_r/;
     eye_rect.bottom=eye_py+eye_r/;
     return ;
 }
 int drawHand(HDC hdc)
 {
     /**< 画嘴 */
     if(cat==)
     {
         MoveToEx (hdc, width/+width/,height/*, NULL) ;
         LineTo (hdc, width*/-width/, height/*) ;
         SelectObject (hdc,gray_brush ) ;
         Ellipse(hdc,width/-width/,height/*,width/+width/,height*1.1);//左胳膊
         Ellipse(hdc,width/*-width/,height/*,width/*+width/,height*1.1);//右胳膊
         return ;
     }
     SelectObject (hdc, gray_brush) ;
     Ellipse(hdc,width/*-width/,height/*,width/*+width/,height*1.1);//右胳膊
     Ellipse(hdc,width/-width/,height-height/,width/+width/,height);//左胳膊
     /**< 画脚掌 */
     Ellipse(hdc,width/-width/,height-height/,width/+width/,height);
     MoveToEx (hdc, width/-width/,height-height/, NULL) ;
     LineTo (hdc, width/-width/, height-height/) ;
     MoveToEx (hdc, width/,height-height/, NULL) ;
     LineTo (hdc, width/, height-height/) ;
     MoveToEx (hdc, width/+width/,height-height/, NULL) ;
     LineTo (hdc, width/+width/, height-height/) ;
     Arc( hdc, width/-width/, height-height/,width/+width/, height,width/+width/, height,width/-width/, height);
     /**< 画嘴 */
     Arc( hdc, width*/+width/,  height/*,width*/-width/, height/*,width*/, height/*, width*/, height/*);
     return ;
 }
 LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 {
     POINT pc;
     HDC hdc;
     switch (message)
     {
     case WM_CREATE:
         init(hwnd);
         initGraph =;
         InvalidateRect (hwnd,NULL, true) ;
         return  ;
     case WM_SIZE:
         init(hwnd);
         initGraph =;
         InvalidateRect (hwnd,NULL, true) ;
         return ;
     case WM_MOVE:
         return ;
     case WM_LBUTTONDOWN:
         GetCursorPos(&pc);
         if(pc.x==sp.x&&pc.y==sp.y)
         {
             cat=;
             SetCursorPos(sp.x,sp.y-height/);
             ReleaseCapture () ;
             initGraph=;
             InvalidateRect (hwnd,NULL,  true) ;
         }
         return  ;
     case WM_MOUSEMOVE:
         if(cat==)
         {
             SetCursorPos(sp.x,sp.y);
             return ;
         }
         GetCursorPos(&p);
         pp=p;
         ScreenToClient(hwnd,&pp);
         if((pp.x>width/-width/)&&(pp.x<width/+width/)&&(pp.y>height-height/)&&(pp.y<height))
         {
             SetCapture (hwnd) ;
             sp.x=width/;
             sp.y=height-height/;
             ClientToScreen(hwnd,&sp);
             cat=;
             initGraph=;
             InvalidateRect (hwnd,NULL, true) ;
             return ;
         }
         k=999.0;
         if(pp.x-left_eye_px!=)
         {
             k=(pp.y-eye_py)/(pp.x-left_eye_px);
         }
         deltax=(ball_hr/)/(+k*k);
         deltax=sqrt(deltax);
         if(!(pp.x>left_eye_px))
         {
             deltax=(-1.0)*deltax;
         }
         px=left_eye_px+deltax*;
         deltax=(ball_hr/)/(+/(k*k));
         deltax=sqrt(deltax);
         if(!(pp.y>eye_py))
         {
             deltax=(-1.0)*deltax;
         }
         py=eye_py+deltax*;
         k=999.0;
         if(pp.x-right_eye_px!=)
         {
             k=(pp.y-eye_py)/(pp.x-right_eye_px);
         }
         deltax=(ball_hr/)/(+k*k);
         deltax=sqrt(deltax);
         if(!(pp.x>right_eye_px))
         {
             deltax=(-1.0)*deltax;
         }
         ppx=right_eye_px+deltax*;
         deltax=(ball_hr/)/(+/(k*k));
         deltax=sqrt(deltax);
         if(!(pp.y>eye_py))
         {
             deltax=(-1.0)*deltax;
         }
         ppy=eye_py+deltax*;
         InvalidateRect (hwnd, &eye_rect, false) ;
         return  ;
     case WM_PAINT:
         hdc=BeginPaint (hwnd,&ps) ;
         if(initGraph==)
         {
             SelectObject (hdc, gray_brush) ;
             Ellipse(hdc,width/,height/,width-width/,height*/);//身体
             /**< 画脸 */
             Ellipse(hdc,,height/,width*/,height*/);
             /**< 画耳朵 */
             pts[].x =width/;
             pts[].y =height/;
             pts[].x =width/;
             pts[].y =height/*;
             pts[].x =width/*;
             pts[].y =height/*;
             Polygon (hdc, pts, ) ;
             pts[].x =width/*;
             pts[].y =height/;
             pts[].x =width/*;
             pts[].y =height/*;
             pts[].x =width/*;
             pts[].y =height/*;
             Polygon (hdc, pts, ) ;
             /**< 画胡子 */
             MoveToEx (hdc, , height/*, NULL) ;
             LineTo (hdc, width/*,height/*) ;
             MoveToEx (hdc, , height/*, NULL) ;
             LineTo (hdc, width/*,height/*) ;
             MoveToEx (hdc, , height/*, NULL) ;
             LineTo (hdc, width/*,height/*) ;
             MoveToEx (hdc, width, height/*, NULL) ;
             LineTo (hdc, width/*,height/*) ;
             MoveToEx (hdc, width, height/*, NULL) ;
             LineTo (hdc, width/*,height/*) ;
             MoveToEx (hdc, width, height/*, NULL) ;
             LineTo (hdc, width/*,height/*) ;
             drawHand(hdc);
             initGraph=;
         }
         /**< 画眼睛 */
         SelectObject (hdc, white_brush) ;
         drawRound(hdc,left_eye_px,eye_py,eye_r);
         drawRound(hdc,right_eye_px,eye_py,eye_r);
         SelectObject (hdc, black_brush) ;
         drawRound(hdc,px,py,ball_hr*);
         drawRound(hdc,ppx,ppy,ball_hr*);
         EndPaint (hwnd, &ps) ;
         return  ;
     case WM_DESTROY:
         PostQuitMessage () ;
         return  ;
     }
     return DefWindowProc (hwnd, message, wParam, lParam) ;
 }

程序写于大三上学期，Windows程序设计 课程考核作业。

2016.4.12更新博客。

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