private void testSetNavigationTree_AfterSelect( object sender, TreeViewEventArgs e )
{
var fi = e.Node.Tag as FileInfo;
var di = e.Node.Tag as DirectoryInfo;
bool ctrlKey = ModifierKeys == Keys.Control;
bool shftKey = ModifierKeys == Keys.ShiftKey;
if (ctrlKey)
ProcessControlSelectedTreeKeys( e );
else if (shftKey)
ProcessShiftSelectedTreeKeys( e );
else
ProcessSingleSelectedTreeNode( e );
_navigator.SelectedFile = _firstTreeNode.Tag as FileInfo;
}