public GDITest1()
        {
            InitializeComponent();
        }

        private void GDITest1_Paint(object sender, PaintEventArgs e)
        {
            Graphics g = e.Graphics; //创建画板,这里的画板是由Form提供的.
            Pen p = new Pen(Color.Gray, 2);//定义了一个蓝色,宽度为的画笔
            g.DrawLine(p, 10, 10, 100, 100);//在画板上画直线,起始坐标为(10,10),终点坐标为(100,100)
            //g.DrawRectangle(p, 10, 10, 100, 100);//在画板上画矩形,起始坐标为(10,10),宽为,高为
             
            int i = 0;
            while (i <10)
            {
                i++;
                int f = i * 10;
                g.DrawEllipse(p, f, f, f, f);//在画板上画椭圆,起始坐标为(10,10),外接矩形的宽为,高为
                Thread.Sleep(1000);
              
            }
        }