public void OpenWindow()
 {
     lock (windowLockObj_) {
         if (window_ == null)
         {
             window_             = new Views.TweetWindow();
             window_.Owner       = Application.Current.MainWindow;
             window_.DataContext = TweetVM;
             window_.Show();
             IsWindowOpen = true;
         }
     }
 }
 public void CloseWindow()
 {
     lock (windowLockObj_) {
         if (window_ != null)
         {
             if (window_.IsVisible)
             {
                 window_.Close();
             }
             window_ = null;
         }
         IsWindowOpen = false;
     }
 }
 public void OpenWindow()
 {
     lock (windowLockObj_) {
         if (window_ == null) {
             window_ = new Views.TweetWindow();
             window_.Owner = Application.Current.MainWindow;
             window_.DataContext = TweetVM;
             window_.Show();
             IsWindowOpen = true;
         }
     }
 }
 public void CloseWindow()
 {
     lock (windowLockObj_) {
         if (window_ != null) {
             if (window_.IsVisible) {
                 window_.Close();
             }
             window_ = null;
         }
         IsWindowOpen = false;
     }
 }