RadTreeView fully supports checkboxes, which are displayed next to the TreeNodes. You can enable the checkboxes mode by setting the CheckBoxes attribute to "True".

By default, all TreeNodes will display checkboxes if the CheckBoxes attribute is set to "True". However you can disable a checkbox for a particular TreeNode by settings its Checkable attribute to "False" (in the XML ContentFile).
You can retrieve all checked TreeNodes upon postback at the server-side by using the CheckedNodes property, which returns an ArrayList collection of the TreeNodes that have been checked in the browser.

                                                  
This example demonstrates also the use of the BeforeClient{EventName} and AfterClient{EventName} JavaScript event handlers, which allow fine-tuning of the RadTreeView behavior.

Here we use the AfterClientCheck event handler to check/uncheck all children nodes in case the parent node is checked/unchecked respectively.

We have also used the BeforeClientCheck event handler to forbid the checking of a TreeNode, according to some criteria.