protected void dataSource_SelectedIndexChanged(object sender, EventArgs e) { if (dataSource.SelectedValue == "XML Data Source") { C1TreeViewNodeBinding binding = new C1TreeViewNodeBinding("treeviewnode"); binding.FormatString = "{0}"; binding.TextField = "Text"; binding.ExpandedField = "Expanded"; binding.ValueField = "Value"; binding.ItemIconClassField = "ItemIconClass"; binding.CollapsedIconClassField = "CollapsedIconClass"; binding.ExpandedIconClassField = "ExpandedIconClass"; C1TreeView1.DataSourceID = "XmlDataSource"; C1TreeView1.DataBindings.Add(binding); } if (dataSource.SelectedValue == "SiteMap Data Source") { C1TreeView1.DataBindings.Clear(); C1TreeView1.DataSourceID = "SiteMapDataSource"; } UpdatePanel1.Update(); }