Create an irregular Region add a circle to the region : Region : Drawing 2D C# Examples

    
using  System;
using  System.Collections.Generic;
using  System.ComponentModel;
using  System.Data;
using  System.Drawing;
using  System.Drawing.Drawing2D;
using  System.Text;
using  System.Windows.Forms;

public  class  Form1  :  Form  {
        protected  override  void  OnPaint(PaintEventArgs  e)  {
                Graphics  g  =  e.Graphics;
                g.FillRectangle(Brushes.White,  this.ClientRectangle);
                Region  reg  =  new  Region();
                reg.MakeEmpty();

                GraphicsPath  gp  =  new  GraphicsPath();
                gp.AddEllipse(10,  10,  50,  50);
                reg.Union(gp);
                gp.Reset();
                gp.AddLine(40,  40,  70,  10);
                gp.AddLine(70,  10,  100,  40);
                gp.CloseFigure();
                reg.Union(gp);
                reg.Union(new  Rectangle(40,  50,  60,  60));
                g.SetClip(reg,  CombineMode.Replace);
                g.FillRectangle(Brushes.Green,  this.ClientRectangle);
                gp.Dispose();
                reg.Dispose();
        }
        public  static  void  Main()  {
                Application.Run(new  Form1());
        }
}