C# 图片框跟随鼠标移动

  　   先贴上代码

　　　private bool isMouseDown = false;
        private Point mouseOffset; //记录鼠标指针的坐标

        private void PicBox_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                mouseOffset.X = e.X;
                mouseOffset.Y = e.Y;
                isMouseDown = true;
            }
        }

        private void PicBox_MouseMove(object sender, MouseEventArgs e)
        {
            if (isMouseDown)
            {
                int left = PicBox.Left + e.X - mouseOffset.X;
                int top = PicBox.Top + e.Y - mouseOffset.Y;
                PicBox.Location = new Point(left,top);
            }
        }

        private void PicBox_MouseUp(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                isMouseDown = false;
            }
        }

　　 事件中的 MouseEventArgs e ：

　　根据e得到的坐标，不是鼠标相对与Form左上角的坐标，而是相对于图片框的左上角坐标,所以算鼠标偏移量的时候，只要计算两次事件对象e中的坐标的差值！

　　保存鼠标按下时相对于图片框左上角的坐标

                mouseOffset.X = e.X;
                mouseOffset.Y = e.Y;

　　移动时得到偏移量

                e.X - mouseOffset.X;
                e.Y - mouseOffset.Y;

     算出图片框的新位置

                int left = PicBox.Left + e.X - mouseOffset.X;
                int top = PicBox.Top + e.Y - mouseOffset.Y;