The Load-On-Demand feature of
RadTreeView allows nodes to be added on
the fly as
nodes are expanded.
The NodeExpand event fires when the "+" icon is clicked. This event
provides the opportunity to add nodes based on the identity of the clicked-on parent
node. The NodeExpand event is fired based on the ExpandMode
property of each node. When the ExpandMode property is set to
ServerSide, this will trigger a postback that fires the NodeExpand
event. When a node is toggled, a postback is performed automatically to retrieve
the data for just that node. Minimally, you must set the ExpandMode
to ServerSide and handle the NodeExpand event
as shown in this example.
This example demonstrates this approach for Sql DataSource - a single self-referencing
table (Id -> ParentId).