title: WPF treeview items clear
body: <p>I am working with WPF <code>TreeView</code>. I have bound the <code>TreeView</code> with it's <code>DataContext</code> property. But whenever I am trying to refresh the <code>TreeView</code> by clearing all the nodes, it's not allowing. I have tried </p>
  
  <p><code>treeview1.Items.Clear();</code></p>
  
  <p>but it throws exception.</p>
  
  <p>Please suggest me how can I solve this problem?</p>