using System; using System.Drawing; using System.Drawing.Imaging; using System.Drawing.Drawing2D; using System.Collections; using System.ComponentModel; using System.Windows.Forms; using System.Data; public class TestGDI1 : System.Windows.Forms.Form{ //in order to paint something OnPaint method needs to be overridden protected override void OnPaint(System.Windows.Forms.PaintEventArgs pe) { //OnPaint method is a member of Form class //The following call sends pe to an event listener Graphics base.OnPaint(pe); //initialize Graphics System.Drawing.Graphics g=pe.Graphics; //designate the area of the form where the drawing must take place //ClientRectangle is a member of Windows.Forms.Control class System.Drawing.Rectangle client_area=this.ClientRectangle; //point11 is at the top left corner of the client_area System.Drawing.Point point11=new System.Drawing.Point(client_area.X,client_area.Y); //point12 is at the bottom right corner of the client area System.Drawing.Point point12=new System.Drawing.Point(client_area.Width,client_area.Height); //create a Brush object of white color //SolidBrush means that the color does not change from point to point System.Drawing.Brush background=new System.Drawing.SolidBrush(System.Drawing.Color.White); //color client_area with solid white brush g.FillRectangle(background,client_area); //make red and blue pens System.Drawing.Pen p=new System.Drawing.Pen(System.Drawing.Color.Red); System.Drawing.Pen p1=new System.Drawing.Pen(System.Drawing.Color.Blue); //create points and rectangles System.Drawing.SizeF size=new System.Drawing.SizeF(); size.Height=160; size. Width=180; System.Drawing.PointF point=new System.Drawing.PointF(); point.X=8; point.Y=40; System.Drawing.Point point1=new System.Drawing.Point(); point1.X=300; point1.Y=300; System.Drawing.Point point2=new System.Drawing.Point(); point2.X=0; point2.Y=0; System.Drawing.RectangleF rec =new System.Drawing.RectangleF(point,size); //draw an ellipse inscribed in the invisible rectangle rec //to change the size or shape of the ellipse change an invisible rectangle in which it is inscribed //to change the color of the ellipse, change the color of the pen p which is used to draw it g.DrawEllipse(p,rec); //draw a line between a pair of points point1 and point2 with pen p1 g.DrawLine(p1,point1,point2); } public static void Main() { System.Windows.Forms.Application.Run(new TestGDI1());//display form } }