ComboBox selected item changed event 2 : ComboBox : GUI Windows Form C# Source Code

    

using System;
using System.Drawing;
using System.Windows.Forms;


public class Test : Form {
 
  private RadioButton square = new RadioButton();
  private RadioButton circle = new RadioButton();
  private ComboBox color = new ComboBox();
 
  private Color c = Color.Red;
 
  public Test( ) {
    Text = "Select Item";
    square.Text = "Square";
    circle.Text = "Circle";
    color.Text = "Choose a color";
 
    Size = new Size(400,250);
 
    int w = 20;
    square.Location = new Point(w, 30);
    circle.Location = new Point(w += 10 + square.Width, 30);
    color.Location = new Point(w += 10 + circle.Width, 30);
 
    color.Items.Add("Red");
    color.Items.Add("Green");
    color.Items.Add("Blue");
 
    Controls.Add(square);
    Controls.Add(circle);
    Controls.Add(color);
 
    square.CheckedChanged += new EventHandler(Checked_Changed); 

    circle.CheckedChanged += new EventHandler(Checked_Changed); 

    color.SelectedIndexChanged += new EventHandler(Selected_Index); 
  }
 
  protected override void OnPaint(PaintEventArgs e){
    Graphics g = e.Graphics;
    Brush brush = new SolidBrush(c);
    if (square.Checked)
      g.FillRectangle(brush,100,100,100,100);
    else
      g.FillEllipse(brush,100,100,100,100);
    base.OnPaint( e );
  }
 
  protected void Selected_Index(Object sender, EventArgs e){
    if (color.SelectedItem.ToString() == "Red" )
      c = Color.Red;
    else if (color.SelectedItem.ToString() == "Green")
      c = Color.Green;
    else
      c = Color.Blue;
    Invalidate();
  }
 
  protected void Checked_Changed(Object sender, EventArgs e) {
    Invalidate();
  }
  static void Main() {
    Application.Run(new Test());
  }
}