The RadioButtonList displays a collection of radio buttons on a web page. There can only be one selection in a group of choices at a time. In this tutorial we will create a RadioButtonList and then bind it to the Categories table of the Northwind database using a DataTable.

To create a RadioButtonList control do the following:

1.  Select the "RadioButtonList" control under the "Standard" control in the "Toolbox" pane on the left.



2.  Drag the RadioButtonList control to a design surface


3.  In the source code of the .aspx page make sure "AutoPostBack" is set to true, the source code should look like this

<asp:RadioButtonList ID="RadioButtonList1" runat="server" 
AutoPostBack="true">
</asp:RadioButtonList>

4. Create a connection string in the Web.Config file

  <connectionStrings>
    <add name="NorthwindConnectionString" connectionString="Data Source=(local);
Initial Catalog=Northwind;Integrated Security=True" 
providerName="System.Data.SqlClient"/>
  </connectionStrings>

5. Create a new folder in your project call "BusinessObjects" then add a .cs file call "Category.cs"

6. In the "Category.cs" file type in the following code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace BusinessObjects
{
    public class Category
    {
        private int _categoryID;
        private string _categoryName;

        public Category(int Id, string Name)
        {
            this._categoryID = Id;
            this._categoryName = Name;
        }


        public int CategoryID
        {
            get { return this._categoryID; }
            set { this._categoryID = value; }
        }

        public string CategoryName
        {
            get { return this._categoryName; }
            set { this._categoryName = value; }
        }

    }
}   

7.  In the code behind page(.cs) page of the .aspx page, type in the following lines at the top to use the following libraries

using System.Web.Configuration;
using System.Data.SqlClient;
using System.Data;
using BusinessObjects;

8. Create a new method call BindCategoriesRadioButtonListObjects() that returns void

  

        protected void BindCategoriesRadioButtonListObjects()
        {
            DataTable dtCategories = new DataTable();
            string connectString = WebConfigurationManager.ConnectionStrings["NorthwindConnectionString"].ConnectionString;
            List categories = new List();

            using (SqlConnection conn = new SqlConnection(connectString))
            {
                SqlCommand cmd = new SqlCommand("SELECT CategoryID,CategoryName FROM Categories", conn);
                conn.Open();
                SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                adapter.Fill(dtCategories);


                foreach (DataRow row in dtCategories.Rows)
                {
                    categories.Add(new Category(Convert.ToInt32(row["CategoryID"].ToString()), row["CategoryName"].ToString()));
                }

                //used to set the RadioButtonList1.DataSource to categories list of objects
                RadioButtonList1.DataSource = categories;

                RadioButtonList1.DataTextField = "CategoryName";

                RadioButtonList1.DataValueField = "CategoryID";
                RadioButtonList1.DataBind();

            }


        }