//the class PaintEventArgs provides data for the object event Paint private void panelDrawing_Paint(object sender, PaintEventArgs e) { // Fill before painting to have a lighter border // Rectangle if (this.radioButtonRectangle.Checked == true && myRectangle != null) { if (fill) { myRectangle.Fill(e); } myRectangle.Draw(e); this.textBoxDisplay.Text = myRectangle.ToString(); } // Square if (this.radioButtonSquare.Checked == true && mySquare != null) { if (fill) { mySquare.Fill(e); } mySquare.Draw(e); this.textBoxDisplay.Text = mySquare.ToString(); } // Circle if (this.radioButtonCircle.Checked == true && myCircle != null) { if (fill) { myCircle.Fill(e); } myCircle.Draw(e); this.textBoxDisplay.Text = myCircle.ToString(); } // Ellipse if (this.radioButtonEllipse.Checked == true && myEllipse != null) { if (fill) { myEllipse.Fill(e); } myEllipse.Draw(e); this.textBoxDisplay.Text = myEllipse.ToString(); } }