OnClientCheckedStateChanging

The OnClientCheckedStateChanging client-side event occurs before a button has been checked.

To check a button it should be marked with CheckOnClick="True"

The event handler receives two parameters:

1. The instance of the toolbar firing the event.

2. An eventArgs parameter containing the following methods:

• get_item returns a reference to the toolbar item that was checked. In this case this is a RadToolBarButton

• set_cancel lets you prevent the drop-down from checking

• get_domEvent returns the browser's event object

You can use this event to respond when a button has been checked.

<script type="text/javascript">
    function checkedStateChanging(sender, args) {
        args.set_cancel(true);
    }        
</script> 
<telerik:RadToolBar RenderMode="Lightweight" ID="RadToolBar1" runat="server" 
    OnClientCheckedStateChanging="checkedStateChanging">    
    <Items>        
        <telerik:RadToolBarButton Text="Button1" CheckOnClick="true">
        </telerik:RadToolBarButton>        
        <telerik:RadToolBarButton Text="Button1" CheckOnClick="true">
        </telerik:RadToolBarButton>        
        <telerik:RadToolBarButton Text="Button1" CheckOnClick="true">
        </telerik:RadToolBarButton>    
    </Items>
</telerik:RadToolBar>