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Getting Started with the Telerik WebForms CheckBoxList

Updated on Aug 24, 2026

The following help article demonstrates how to set up a page with a RadCheckBoxList control and use its OnSelectedIndexChanged server event:

In the default page of a new ASP.NET AJAX-enabled Web Application, add a RadCheckBoxList control:
ASP.NET
```
<telerik:RadCheckBoxList ID="RadCheckBoxList1" runat="server">
</telerik:RadCheckBoxList>
```

Add two ButtonListItem objects to the Items collection and set the appropriate values for Text and Selected properties of each item:

ASP.NET

<telerik:RadCheckBoxList ID="RadCheckBoxList1" runat="server">
	<Items>
		<telerik:ButtonListItem Text="Accept" Value="0" Selected="true" />
		<telerik:ButtonListItem Text="Decline" Value="1" />
	</Items>
</telerik:RadCheckBoxList>

To hook to the OnSelectedIndexChanged server-side event of RadCheckBoxList, add an attribute to the main control tag and add the method signature:

ASP.NET

<telerik:RadCheckBoxList ID="RadCheckBoxList1" runat="server" OnSelectedIndexChanged="RadCheckBoxList1_SelectedIndexChanged">
	<Items>
		<telerik:ButtonListItem Text="Accept" Value="0" Selected="true" />
		<telerik:ButtonListItem Text="Decline" Value="1" />
	</Items>
</telerik:RadCheckBoxList>

protected void RadCheckBoxList1_SelectedIndexChanged(object sender, EventArgs e)
{

}

Protected Sub RadCheckBoxList1_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
End Sub

Add a Label control to write the information to:
ASP.NET
```
<asp:Label ID="Label1" Text="" runat="server" />
```

Use the OnSelectedIndexChanged event handler to write information about the properties of the SelectedItem of the RadCheckBoxList:

protected void RadCheckBoxList1_SelectedIndexChanged(object sender, EventArgs e)
{
	RadCheckBoxList checkboxlist = sender as RadCheckBoxList;


		string data = string.Format("selected index: {0}, selected value {1}, selected text: {2}",
									checkboxlist.SelectedIndex, checkboxlist.SelectedValue, checkboxlist.SelectedItem.Text);
	Label1.Text = data;
}

Protected Sub RadCheckBoxList1_SelectedIndexChanged(sender As Object, e As EventArgs)
	Dim checkboxlist As RadCheckBoxList = TryCast(sender, RadCheckBoxList)


		Dim data As String = String.Format("selected index: {0}, selected value {1}, selected text: {2}", checkboxlist.SelectedIndex, checkboxlist.SelectedValue, checkboxlist.SelectedItem.Text)
	Label1.Text = data
End Sub

Getting Started with the Telerik WebForms CheckBoxList

See Also