C# 窗体圆角制作

using   System.Drawing.Drawing2D;

protected   override   void   OnPaint(   System.Windows.Forms.PaintEventArgs   e   )      

 {       

GraphicsPath   oPath   =   new   GraphicsPath();       

int   x=0;       

int   y=0;       

int   w=Width;       

int   h=Height;       

int   a=40;       

Graphics   g=CreateGraphics();       

oPath.AddArc(x,y,a,a,180,90);       

oPath.AddArc(w-a,y,a,a,270,90);       

oPath.AddArc(w-a/2,h-a/2,a/2,a/2,0,90);       

oPath.AddArc(x,h-a,a,a,90,90);       

oPath.CloseAllFigures();       

Region=new   Region(oPath);      

}