title: how to use INotifyPropertyChanged on treeview wpf
body: <p>I dont know if the title question is right, but i'm writing a program that wheמ a client connects to my server i can reach all of his files using tree view and i do that by presssing on the listboxitem representig the client, and then i can view his files.
  But when I press another client I see the the tree view of the first client that I pressed on the first time, I tried to use INotifyPropertyChanged but i didnt figured out how to use it.
  I want to save the proprties of the tree view,
  I also tried to do(trvStructure is the clients files tree view): <code>trvStructure=new TreeView()</code> and <code>trvStructure=null</code> every time i select new client from the list box but none of them works.
  Is there another way to do it?
  Also I thing it’s important to say that the tree view items are created manually by code</p>