Question

 I want to restrict the user from seeing the tree item contents… if user tries to click on parent tree item .. [+] the child tree item should not be shown.. that is what I wish to restrict.< ?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

Answer

Implement IphGantX3.OnTreeExpand and set the Allow parameter to false. It will do the trick.