RadControls for ASP.NET AJAX The DataItem property is available only during databinding in the NodeDataBound event:
CopyC#
protected void RadTreeView1_NodeDataBound(object o, RadTreeNodeEventArgs e)
{
DataRowView dataSourceRow = (DataRowView)e.Node.DataItem;
}CopyVB.NET
Protected Sub RadTreeView1_NodeDataBound(ByVal o As Object, ByVal e As RadTreeNodeEventArgs)
Dim dataSourceRow As DataRowView = CType(e.Node.DataItem, DataRowView)
End SubYou should not use it elsewhere. You can use the Value property or Custom Attributes instead.