public void DisplayLogWindow()
 {
     if (_logViewer == null)
     {
         _logViewer          = new LogViewerWindow(_logViewerViewmodel);
         _logViewer.Closing += _logViewer_Closing;
     }
     _logViewer.Show();
 }
 public void ShutSubsidiaryWindows()
 {
     if (_logViewer != null)
     {
         _logViewer.Close();
         _logViewer = null;
     }
     if (_helpWindow != null)
     {
         _helpWindow.Close();
         _helpWindow = null;
     }
 }
 void _logViewer_Closing(object sender, CancelEventArgs e)
 {
     _logViewer = null;
 }