Hi Liping,
As a third-party tree control with the ClrUiTreeCtrl class name is used in your app, it's difficult to tell for sure what property or method you need to use. That would be great if you created a sample app containing the control and shared it with us - in this case, we could play with it.
You should be able to test the control via its native properties and methods. Try exploring
TestComplete's Object Browser to find the needed one. To make sure that you see all properties/methods of the object, switch to
the Advanced View mode and make TestComplete show hidden properties (
Tools | Options | Engines | General | Display members | Show hidden members).
