c# 重绘窗体 控件为不规则形状

protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);
            System.Drawing.Drawing2D.GraphicsPath shape = new System.Drawing.Drawing2D.GraphicsPath();
            shape.AddEllipse(0, 0, this.Height, this.Width);
            this.Region = new Region(shape);
        }