C# WinForm 绘制圆角窗体

 public void SetWindowRegion()
        {

            System.Drawing.Drawing2D.GraphicsPath FormPath;

            FormPath = new System.Drawing.Drawing2D.GraphicsPath();

            Rectangle rect = new Rectangle(, , this.Width, this.Height - );//this.Left-10,this.Top-10,this.Width-10,this.Height-10);                 

            FormPath = GetRoundedRectPath(rect, );

            this.Region = new Region(FormPath);

        }

        private GraphicsPath GetRoundedRectPath(Rectangle rect, int radius)
        {

            int diameter = radius;

            Rectangle arcRect = new Rectangle(rect.Location, new Size(diameter, diameter));

            GraphicsPath path = new GraphicsPath();

            //   左上角   

            path.AddArc(arcRect, , );

            //   右上角   

            arcRect.X = rect.Right - diameter;

            path.AddArc(arcRect, , );

            //   右下角   

            arcRect.Y = rect.Bottom - diameter;

            path.AddArc(arcRect, , );

            //   左下角   

            arcRect.X = rect.Left;

            path.AddArc(arcRect, , );

            path.CloseFigure();

            return path;

        }

        protected override void OnResize(System.EventArgs e)
        {

            this.Region = null;

            SetWindowRegion();

        }