c_cpp 鼠标回调函数on_MouseHandle（）

Posted 2021-05-14

//--------------------------------【on_MouseHandle( )函数】-----------------------------
//		描述：鼠标回调函数，根据不同的鼠标事件进行不同的操作
//-----------------------------------------------------------------------------------------------
void on_MouseHandle(int event, int x, int y, int flags, void* param)
{

	Mat& image = *(cv::Mat*) param;
	switch (event)
	{
		//鼠标移动消息
		case EVENT_MOUSEMOVE:
		{
			if (g_bDrawingBox)//如果是否进行绘制的标识符为真，则记录下长和宽到RECT型变量中
			{
				g_rectangle.width = x - g_rectangle.x;
				g_rectangle.height = y - g_rectangle.y;
			}
		}
		break;

		//左键按下消息
		case EVENT_LBUTTONDOWN:
		{
			g_bDrawingBox = true;
			g_rectangle = Rect(x, y, 0, 0);//记录起始点
		}
		break;

		//左键抬起消息
		case EVENT_LBUTTONUP:
		{
			g_bDrawingBox = false;//置标识符为false
			//对宽和高小于0的处理
			if (g_rectangle.width < 0)
			{
				g_rectangle.x += g_rectangle.width;
				g_rectangle.width *= -1;
			}

			if (g_rectangle.height < 0)
			{
				g_rectangle.y += g_rectangle.height;
				g_rectangle.height *= -1;
			}
			//调用函数进行绘制
			DrawRectangle(image, g_rectangle);
		}
		break;
	}
}