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(0, 22, this.Width, this.Height - 22);//this.Left-10,this.Top-10,this.Width-10,this.Height-10);                 

    FormPath = GetRoundedRectPath(rect, 30);

    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, 180, 90);

    //   右上角   

    arcRect.X = rect.Right - diameter;

    path.AddArc(arcRect, 270, 90);

    //   右下角   

    arcRect.Y = rect.Bottom - diameter;

    path.AddArc(arcRect, 0, 90);

    //   左下角   

    arcRect.X = rect.Left;

    path.AddArc(arcRect, 90, 90);

    path.CloseFigure();

    return path;

}

protected override void OnResize(System.EventArgs e)

{

    this.Region = null;

    SetWindowRegion();

}

增加命名空间:using System.Drawing.Drawing2D; 
添加方法如下:当然各角的点可根据需要确定.

private void Type(Control sender, int p_1, double p_2)

{

    GraphicsPath oPath = new GraphicsPath();

    oPath.AddClosedCurve(

        new Point[] {

            new Point(0, sender.Height / p_1),

            new Point(sender.Width / p_1, 0), 

            new Point(sender.Width - sender.Width / p_1, 0), 

            new Point(sender.Width, sender.Height / p_1),

            new Point(sender.Width, sender.Height - sender.Height / p_1), 

            new Point(sender.Width - sender.Width / p_1, sender.Height), 

            new Point(sender.Width / p_1, sender.Height),

            new Point(0, sender.Height - sender.Height / p_1) },



        (float) p_2);



    sender.Region = new Region(oPath);

}