C# RadioButton Example

Simple C# examples to help you learn about the RadioButton components in C#.

This tutorial will help you learn the following concepts:

How to create and use RadioButtons in Windows Forms programmatically.
How to add several controls to a RadioButton
How to set text property of a radiobutton
How to autocheck as well as check a radiobutton programmatically.
How to handle click events of a radiobutton
How to set custom font to a radiobutton
How to handle CheckedChangedevents of a RadioButton.

Contents hide

1 Example 1: Simple RadioButtons

1.1 Step 1: Create Project

1.2 Step 2: Write Code

1.3 Run

1.4 Reference

2 Example 2: GroupBoxAndRadioButton

2.1 Step 1: Create Project

2.2 Step 2: Write Code

2.3 Run

2.4 Reference

Example 1: Simple RadioButtons

This example will comprise the following files:

RadioButton.cs

Step 1: Create Project

The first step is to create a C# Project.
Go to FILE-->New-->Project to create a new project.

Step 2: Write Code

Write Code as follows:

*(a). RadioButton.cs

Create a file named RadioButton.cs

Below are our imports. Included are the System.Windows.Forms:

using System;
using System.Windows.Forms;

The main entry point for the application. Enable VisualStyles and invoke Application.Run()

    public static void Main() {
      Application.EnableVisualStyles();
      Application.Run(new Form1());
    }

Define our Form1 Constructor

    public Form1() {

Add several controls using the AddRange() method. You pass it an array of controls, in this case Radiobuttons

      Controls.AddRange(new Control[] { radioButton1, radioButton2, radioButton3, radioButton4, radioButton5, label1 });

Set text property of the RadioButton using the Text property

      Text = "Radio button example";

You can set the RadioButton to be checked by default using the AutoCheck property

      radioButton1.AutoCheck = false;

You can also set the Checked property to true or false to either check it or uncheck it maybe conditionally

      radioButton1.Checked = true;

To handle click events of a radiobutton assign it a delegate as follows:

      radioButton1.Click += delegate {
        // Uncomments next line to check / uncheck radio button 1 (auto_check is false...)
        //radioButton1.Checked = !radioButton1.Checked;
      };

You can also set the font of a RadioButton using the Font property. Assign it a System.Drawing.Font as follows:

      radioButton1.Font = new System.Drawing.Font(radioButton1.Font, System.Drawing.FontStyle.Italic);

Because we are creating our RadioButton programmatically, rather than by using a designer, assign it a location using the Location property and assign it a System.Drawing.Point object:

      radioButton1.Location = new System.Drawing.Point(30, 30);

You can also listen to radiobutton checked change using the CheckedChanged property and by assigning it a delegate as follows:

      radioButton3.CheckedChanged += delegate (object sender, EventArgs e) {
        label1.Text = string.Format("Radio 3 checked = {0}", radioButton3.Checked);
      };

Define the following radiobuttons and a label as our instance fields:

    private RadioButton radioButton1 = new RadioButton();
    private RadioButton radioButton2 = new RadioButton();
    private RadioButton radioButton3 = new RadioButton();
    private RadioButton radioButton4 = new RadioButton();
    private RadioButton radioButton5 = new RadioButton();
    private Label label1 = new Label();

Here is the full code

using System;
using System.Windows.Forms;

namespace Examples {
  class Form1 : Form {
    public static void Main() {
      Application.EnableVisualStyles();
      Application.Run(new Form1());
    }

    public Form1() {
      Controls.AddRange(new Control[] { radioButton1, radioButton2, radioButton3, radioButton4, radioButton5, label1 });

      Text = "Radio button example";

      radioButton1.AutoCheck = false;
      radioButton1.Checked = true;
      radioButton1.Click += delegate {
        // Uncomments next line to check / uncheck radio button 1 (auto_check is false...)
        //radioButton1.Checked = !radioButton1.Checked;
      };

      radioButton1.Font = new System.Drawing.Font(radioButton1.Font, System.Drawing.FontStyle.Italic);

      radioButton1.Location = new System.Drawing.Point(30, 30);
      radioButton1.Text = "radio 1";

      radioButton2.Location = new System.Drawing.Point(30, 60);
      radioButton2.Text = "radio 2";

      radioButton3.CheckedChanged += delegate (object sender, EventArgs e) {
        label1.Text = string.Format("Radio 3 checked = {0}", radioButton3.Checked);
      };
      radioButton3.Checked = true;
      radioButton3.Location = new System.Drawing.Point(30, 90);
      radioButton3.Text = "radio 3";

      radioButton4.Appearance = Appearance.Button;
      radioButton4.Location = new System.Drawing.Point(30, 120);
      radioButton4.Text = "radio 4";

      radioButton5.AutoCheck = false;
      radioButton5.Appearance = Appearance.Button;
      radioButton5.Checked = true;
      radioButton5.Click += delegate {
        // Uncomments next line to check / uncheck radio button 5 (auto_check is false...)
        //radioButton5.Checked = !radioButton5.Checked;
      };
      radioButton5.Font = new System.Drawing.Font(radioButton1.Font, System.Drawing.FontStyle.Italic);
      radioButton5.Location = new System.Drawing.Point(30, 150);
      radioButton5.Text = "radio 5";
      System.Diagnostics.Debug.WriteLine(string.Format("tb = {0}", radioButton3));

      label1.AutoSize = true;
      label1.Location = new System.Drawing.Point(30, 180);
    }

    private RadioButton radioButton1 = new RadioButton();
    private RadioButton radioButton2 = new RadioButton();
    private RadioButton radioButton3 = new RadioButton();
    private RadioButton radioButton4 = new RadioButton();
    private RadioButton radioButton5 = new RadioButton();
    private Label label1 = new Label();

  }
}

Run

Simply copy the source code into your C# Project,Build and Run. Alternatively download the code using the links provided below, then open the .csproj project, build and run.

Reference

Download the code using the below links:

Number	Link
1.	Download Example
2.	Follow code author

Example 2: GroupBoxAndRadioButton