Unity3d 字体描边

private void MakeStroke(Rect position,string txtString,Color txtColor,Color outlineColor,int outlineWidth )
 {
     position.y-= outlineWidth;
     GUI.color=outlineColor;
     GUI.Label(position, txtString);
     position.y+=outlineWidth*2;
     GUI.Label(position, txtString);
     position.y-=outlineWidth;
     position.x-=outlineWidth;
     GUI.Label(position, txtString);
     position.x+=outlineWidth*2;
     GUI.Label(position, txtString);
     position.x-=outlineWidth;
     GUI.color=txtColor;
     GUI.Label(position, txtString);
 }