The history of the web pages visited by users in a WebBrowser app is displayed in a TreeView. Like IE, when a CommandButton is clicked, the TreeView becomes visible. Clicking the CommandButton again hides the TreeView.

Each node in the TreeView has an unique key which is why if the user wants to view his history more than once, on subsequent views, all the nodes in the TreeView are first removed & then the TreeView is again populated with the same nodes. If I don't remove the nodes first, then it generates an error saying key is not unique.

Is there a way by which I can avoid the extra work of deleting all the nodes & re-populating the TreeView with the same nodes on subsequent views (maybe saving all the nodes somewhere so that the uniqueness of the keys of the nodes can be maintained)?