title: check if scroll bar is clicked with doubleclick in datagrid
body: <p>I need my app to perform a certain action when DataGrid is double clicked. The action should not be performed if a scrollbar is doubleclicked. So I try to see what is doubleclicked:</p>
  
  <pre><code>private void DataGrid_MouseDoubleClick(object sender, MouseButtonEventArgs e)
          {
              Point p = Mouse.GetPosition(this.DataGrid1);
              IInputElement ie = this.DataGrid1.InputHitTest(p);
          }
  </code></pre>
  
  <p>But when I doubleclick a scrollbar, then IInputElement appears to be all sort of stuff:
  Microsoft.Windows.Themes.ScrollChrome or System.Windows.Shapes.Rectangle . So I am not sure if I clicked a scrollbar. </p>
  
  <p>So how do I check if I really doubleclicked a scrollbar?</p>