ASP.NET - List Control - Radiobutton

A radiobutton list is a user interface element that presents a list of options, where only one option can be selected at a time. Each option is represented by a radiobutton, which is a small circular button that can be selected by the user. When a radiobutton is selected, it is highlighted and the other radiobuttons in the list are automatically deselected.

Here are some of the main events, methods, and properties associated with radiobutton lists:

Events:

• SelectedIndexChanged: This event is triggered when the selected radiobutton in the list changes.

Methods:

• Add: Adds a new radiobutton to the list.
• Clear: Removes all radiobuttons from the list.
• FindByText: Finds the radiobutton with the specified text in the list.
• FindByValue: Finds the radiobutton with the specified value in the list.

Properties:

• SelectedIndex: Gets or sets the index of the selected radiobutton in the list.
• SelectedValue: Gets or sets the value of the selected radiobutton in the list.
• Items: Gets a collection of all the radiobuttons in the list.

Example

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="RadioButtonListExample.aspx.cs" Inherits="WebApplication1.RadioButtonListExample" %>



    
    

Select Your Country of Residence
            
                
                
                
                
                
            
            

            

            
            

            

            
        
    

In the code-behind file, we can handle the Click event of the submit button and retrieve the selected country from the radio button list:

using System;
using System.Web.UI.WebControls;
namespace WebApplication1
{
    public partial class RadioButtonListExample : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
        }
        protected void SubmitButton_Click(object sender, EventArgs e)
        {
            string selectedCountry = CountryList.SelectedValue;
            ResultLabel.Text = "Your country of residence is: " + selectedCountry;
        }
    }
}

When the user clicks the submit button, the selected country is retrieved and displayed in a label on the page.