@(Html.Kendo().PanelBar()
    .Name("panelbar")
    .ExpandMode(PanelBarExpandMode.Single)
    .Events(events => events
        .DataBound("databound")
    )
    .Items(panelbar =>
    {
        panelbar.Add().Text("Root1")
            .Expanded(true)
            .Items(items =>
            {
                items.Add().Text("Sub-Item 2.1");
                items.Add().Text("Sub-Item 2.2");
            });

        panelbar.Add().Text("Root2")
            .Items(items =>
            {
                items.Add().Text("Sub-Item 2.1");
                items.Add().Text("Sub-Item 2.2");
            });
    })
)

<script>
    function databound(e) {
        alert('databound');
    }
</script>