Single Click Button

The single click button (Figure 1) is used to avoid multiple postbacks/callbacks to the server. This feature is useful in database and/or e-mail send scenarios when the developer should prevent submitting of identical content multiple times to the server.

The single click functionality is available only for buttons that make postbacks. For example the functionality is not available for the LinkButton because it acts as an anchor element.

When the single click functionality is enabled, the button is rendered as <button type="button"> instead of a <button type="submit"> and that takes precedence over the UseSubmitBehavior property.

Figure 1: RadButton with SingeClick functionality before and after click.

The following properties should be used to enable the single click functionality:

• SingleClick - determines whether the RadButton control will be immediately disabled after the user clicks it. Set it to true to enable the single click functionality.

• SingleClickText - determines the text displayed in the RadButton control after the button is being clicked and disabled.

Example 1: The code that enables the single click functionality in RadButton from Figure 1.

ASP.NET

<asp:TextBox ID="txtName" runat="server" />

<telerik:RadButton RenderMode="Lightweight" ID="btnSubmit" runat="server" Text="Submit" OnClick="btnSubmit_Click"
	SingleClick="true"  SingleClickText="Processing...">
</telerik:RadButton>

<asp:Label ID="lblGreeting" runat="server" />

C#

protected void btnSubmit_Click(object sender, EventArgs e)
{
	if (Page.IsPostBack) System.Threading.Thread.Sleep(3000);
	lblGreeting.Text = String.Format("Hello, {0}!", txtName.Text);
}

VB

Protected Sub btnSubmit_Click(sender As Object, e As System.EventArgs) Handles btnSubmit.Click
	If Page.IsPostBack Then
		System.Threading.Thread.Sleep(3000)
	End If
	lblGreeting.Text = String.Format("Hello, {0}!", txtName.Text)
End Sub

The submitted text is processed on the server-side. Note that the method System.Threading.Thread.Sleep is used so that the disabled button can be examined after clicking it.

See Also

• Single Click Button Demo