Accessing the Embedded Tree
When creating the RadDropDownTree control we embedded the RadTreeView control in the dropdown. By using the properties and methods described below you can easily access the RadTreeView control on the client and server side.
Note that once you have access to the tree there might be unexpected behavior of the control. Since we use the RadTreeView control as embedded tree it is also important to clarify that not all scenarios that can be implemented with the RadTreeView control are supported for the RadDropDownTree. Accessing the embedded tree is available with the Q2 2013 SP1 (version 2013.2.717 of the RadControls.)
Server side
In order to access the tree in the dropdown on the server side you will need to use the EmbeddedTree property. It provides reference to the embedded tree and you can easily use all of the properties and methods that are exposed with the tree control. In case the checkbox property of the RadDropDownTree is enabled you will need to also use the SyncEmbeddedTree() method of the RadDropDownTree to create entries in the entries area. Thus, you are synchronizing the tree in the dropdown with the entry area box. Here is an example demonstrating how this looks in code behind:
protected void Page_Load(object sender, EventArgs e)
{
RadDropDownTree1.EmbeddedTree.Nodes.FindNodeByText("Node1").Checked = true;
RadDropDownTree1.SyncEmbeddedTree();
}
Client side
To access the tree object from the client side you need to use the get_embeddedTree() as demonstrated below:
<script>
function pageLoad() {
var dropdowntree1 = $find("RadDropDownTree1");
var tree = dropdowntree1.get_embeddedTree();
var node1 = tree.get_nodes().getNode(0);
}
</script>