鼠标事件例程

鼠标事件类型

CV_EVENT_MOUSEMOVE

0

CV_EVENT_LBUTTONDOWN

1

CV_EVENT_RBUTTONDOWN

2

CV_EVENT_MRUTTONDOWN

3

CV_EVENT_LBUTTONUP

4

CV_EVENT_RBUTTONUP

5

CV_EVENT_MBUTTONUP

6

CV_EVENT_LBUTTONDBLCLK

7

CV_EVENT_RBUTTONDBLCLK

8

CV_EVENT_MBUTTONDBLCLK

9

鼠标事件标志

CV_EVENT_FLAG_LBUTTON

1

CV_EVENT_FLAG_RBUTTON

2

CV_EVENT_FLAG_MBUTTON

3

CV_EVENT_FLAG_CTRLKEY

8

CV_EVENT_FLAG_SHIFTKEY

16

CV_EVENT_FLAG_ALTKEY

32

用鼠标画矩形

//鼠标事件注册
void cvSetMouseCallback(const char* window_name,CvMouseCallback on_mouse,void* param = NULL);

#include "cv.h"
#include "highgui.h"
//鼠标事件声明
void my_mouse_callback(int event,int x,int y,int flags,void* param);
//声明矩形
CvRect box;
//画矩形的标志变量
bool drawing_box = false;
//在图像上画一个矩形
void draw_box(IplImage* img,CvRect rect)
{
    cvRectangle(img,cvPoint(box.x,box.y),cvPoint(box.x+box.width,box.y+box.height),cvScalar(0xff,0x00,0x00));
}

int main(int argc,char** argv)
{
    box = cvRect(-1,-1,0,0);

    IplImage* image = cvCreateImage(cvSize(200,200),IPL_DEPTH_8U,3);
    cvZero(image);

    IplImage* temp = cvCloneImage(image);
    cvNamedWindow("Example3_6",0);

    //注册鼠标事件
    cvSetMouseCallback("Example3_6",my_mouse_callback,(void*)image);

    while (1)
    {
         cvCopyImage(image,temp);
         if (drawing_box)
         {
             draw_box(temp,box);
         }
         cvShowImage("Example3_6",temp);
         if (cvWaitKey(15) == 27)
         {
             break;
         }
    }
    cvReleaseImage(&image);
    cvReleaseImage(&temp);
    cvDestroyAllWindows();
}
void my_mouse_callback(int event,int x,int y,int flags,void* param)
{
    IplImage* image = (IplImage*)param;
    switch (event)
    {
    case CV_EVENT_MOUSEMOVE:
         {
             if (drawing_box)
             {
                 box.width = x - box.x;
                 box.height = y - box.y;
             }
         }
         break;
    case CV_EVENT_LBUTTONDOWN:
         {
             drawing_box = true;
             box = cvRect(x,y,0,0);
         }
         break;
    case CV_EVENT_LBUTTONUP:
         {
             drawing_box = false;
             if (box.width < 0)
             {
                 box.x +=box.width;
                 box.width *= -1;
             }
             if (box.height <0)
             {
                 box.y += box.height;
                 box.height *= -1;
             }
             draw_box(image,box);
         }
         break;
    default:
         break;
    }
}