GDI+ Point size

1,point 和size可以互相转换，如：

   Point p = new Point(300, 300);
            p.Offset(12,14);
            Size s = new Size(12, 12);
            p = (Point)s;  //size转换为point
            s = (Size)p;    //point转换为size

 2.两个矩形的交集

        

         Graphics g = e.Graphics;

           g.Clear(Color.White);

            Rectangle rr = new Rectangle(55,55,100,100);
            Rectangle r2 = new Rectangle(5,5,60,120);
          Rectangle r3 =  Rectangle.Intersect(rr,r2);
          g.FillRectangle(Brushes.Blue, rr);
          g.FillRectangle(Brushes.Black,r2);
         g.FillRectangle(Brushes.DeepPink, r3);