C#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)