protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
 {
     if (geoQ.IsBusy == true)
     {
         geoQ.CancelAsync();
     }
 }

 private void frame_Navigating(object sender, NavigatingCancelEventArgs e)
 {
     if (this.IsBusy)
     {
         this.IsBusy = false;
     }
 }

 private void OnNavigating(object sender, NavigatingCancelEventArgs args)
 {
     _lastMode = args.NavigationMode;
     var handler = Navigating;
     if (handler != null)
         handler(this, new NavigatingCancelEventArgsWrapper(args));
 }

        protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
        {
            // Das Suchen nach Peers beenden
            PeerFinder.Stop();

            base.OnNavigatingFrom(e);
        }

        protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
        {
            Browser.Navigating -= this.Browser_Navigating;
            Browser.NavigationFailed -= this.Browser_NavigationFailed;

            base.OnNavigatingFrom(e);
        }

 protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
 {
     base.OnNavigatingFrom(e);
     var viewModel = DataContext as INavigationAware;
     if (viewModel != null)
         viewModel.OnNavigatingFrom(new NavigatingCancelContext(e.IsCancelable, (NavigationMode)e.NavigationMode, () => e.Cancel, (cancel) => e.Cancel = cancel));
 }

        protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
        {
            if (State.ContainsKey(FocusedElement))
              {
            State.Remove(FocusedElement);
              }

              var focusedElement = FocusManager.GetFocusedElement() as Control;
              if (focusedElement == null) return;
              if (!String.IsNullOrEmpty(focusedElement.Name))
              {
            State.Add(FocusedElement, focusedElement.Name);
              }

              BindingExpression be = null;

              //TODO - Developers, add additional controls here like a date picker, combobox, etc.
              if (focusedElement is TextBox)
              {
            be = focusedElement.GetBindingExpression(TextBox.TextProperty);
              }
              if (be != null)
              {
            be.UpdateSource();
              }
              base.OnNavigatingFrom(e);
        }

        void browser_Navigating(object sender, NavigatingCancelEventArgs e)
        {
            LastUri = e.Uri;
            var uri = e.Uri.ToString();

            // If the configuration has an SuccessUri configured,
            // we check if we should close this window or not incase
            // the browser is arrived on the success page.
            if (!string.IsNullOrEmpty(builder.SuccessUri))
            {
                if (configuration.DisplayName == "Yammer" || configuration.DisplayName == "Facebook")
                {
                    if (uri.Contains(builder.SuccessUri))
                    {
                        Success = true;
                        e.Cancel = true;
                        Close();
                    }
                }
                else
                {
                    if (uri.StartsWith(builder.SuccessUri))
                    {
                        Success = true;
                        e.Cancel = true;
                        Close();
                    }
                }
            }

            addressTextBox.Text = uri;
            loading.Visibility = Visibility.Visible;
            ((Storyboard)FindResource("RunLoaderStoryboard")).Begin();
        }

        protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
        {
            if (_camera == null) return;

            // Dispose camera to minimize power consumption and to expedite shutdown.
            _camera.Dispose();
        }

		protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
		{
			if (this.scanTimer != null)
			{
				this.scanTimer.Stop();
				this.scanTimer.Tick -= this.OnTimerTick;
				this.scanTimer = null;
			}

			if (this.phoneCamera != null)
			{
				this.phoneCamera.CancelFocus();
				this.phoneCamera.Initialized -= this.OnCameraInitialized;
				this.phoneCamera.Dispose();
			}

			if (this.barcodeReader != null)
			{
				this.barcodeReader.ResultFound -= this.OnBarcodeResultFound;
				this.barcodeReader = null;
			}

			if (!this.scanSucceeded && e.NavigationMode == NavigationMode.Back)
			{
				this.BarcodeScannerPlugin.OnScanFailed("Cancelled by user");
			}
		}

        protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
        {
            //clean the view model
            ViewModel.Cleanup();

            base.OnNavigatingFrom(e);
        }

 protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
 {
     webBrowser.Navigating -= webBrowser_Navigating;
     _locationManager.OnPositionDetermined -= _locationManager_OnPositionDetermined;
     _locationManager = null;
     base.OnNavigatingFrom(e);
 }

 protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
 {
     if (e.NavigationMode != NavigationMode.Back)
     {
         ViewModel.Tombstone();
     }
 }

 protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
 {
     if (!alreadyEned)
     {
         EndTest();
     }
 }

        private void BrowserNavigating(object sender, NavigatingCancelEventArgs e)
        {
            if (!e.Uri.ToString().StartsWith(RedirectUri, StringComparison.OrdinalIgnoreCase))
            {
                // we need to ignore all navigation that isn't to the redirect uri.
                return;
            }

            try
            {
                OAuth2Response result = DropboxOAuth2Helper.ParseTokenFragment(e.Uri);
                if (result.State != this.oauth2State)
                {
                    return;
                }

                this.AccessToken = result.AccessToken;
                this.Uid = result.Uid;
                this.Result = true;
            }
            catch (ArgumentException)
            {
                // There was an error in the URI passed to ParseTokenFragment
            }
            finally
            {
                e.Cancel = true;
                this.Close();
            }
        }

        private void Browser_OnNavigating(object sender, NavigatingCancelEventArgs e)
        {
            var url = e.Uri.ToString();

            Logger.LogInfo("--> " + url);

            if (url.Contains("#access_token"))
            {
                var token = url.Split('#')[1].Split('&')[0].Split('=')[1];

                e.Cancel = true;
                _Callback(token);
                Hide();
            }
            //Hide the window when an error is shown... facebook with display its own error in the browser
            //else if (url.Contains("error_code"))
            //{
            //    var queryParameters = url.Split('?')[1].Split('&');
            //    var errorCode = queryParameters.FirstOrDefault(x => x.Contains("error_code")).Split('=')[1];
            //    var errorMessage = queryParameters.FirstOrDefault(x => x.Contains("error_message")).Split('=')[1];

            //    ErrorCode.Content = errorCode;
            //    ErrorMessage.Content = errorMessage;
            //    ErrorInfo.Visibility = Visibility.Visible;
            //    Loader.Visibility = Visibility.Collapsed;
            //    Browser.Visibility = Visibility.Collapsed;
            //}
            else
            {
                Title = "Login";
                Loader.Visibility = Visibility.Collapsed;
                Browser.Visibility = Visibility.Visible;
            }
        }

        void RootFrame_Navigating(object sender, NavigatingCancelEventArgs e)
        {
            //TODO just for testing. Remove folowing line
            /*if(IsolatedStorageSettings.ApplicationSettings.Contains("user")  == false)
                IsolatedStorageSettings.ApplicationSettings.Add("user", API.Mock.UserMock.GetUser());*/
            //End of TODO

            if (IsolatedStorageSettings.ApplicationSettings.Contains("user")  == true 
                || e.Uri.OriginalString.Equals("app://external/"))
            {
                RootFrame.Navigating -= RootFrame_Navigating;
                return;
            }
            else
            {
                e.Cancel = true;
                RootFrame.Dispatcher.BeginInvoke(delegate
                {
                    RootFrame.Navigating -= RootFrame_Navigating;
                    RootFrame.Navigate(new Uri("/LoginRegisterPage.xaml", UriKind.Relative));
                    
                });
            }

        }

 protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
 {
     //stop and reset the game when go away from this page
     isPlaying = false;
     isStarted = false;
     //stop accelerometre reading
     acl.Stop();
     //reset the speed of the ball
     speedX = -5;
     speedY = -5;
     //stop the bar
     speedBar = 0;
     //save the existing amount for new level calculating
     IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
     if (!settings.Contains("Amount"))
     {
         //create the data if it hasn't been created yet
         settings.Add("Amount", rectsAmount.ToString());
     }
     else
     {
         settings["Amount"] = rectsAmount.ToString();
     }
     settings.Save();
 }

        /// <summary>
        /// Executes when leaving the page
        /// </summary>
        /// <param name="e"></param>
        protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
        {
            base.OnNavigatingFrom(e);
            if (!cancel) //if navigation is caused not by pressing the Cancel button
            {
                //default index is the size of App.ViewModel.Tasks - element with default index doesn't exist
                int index = App.ViewModel.Tasks.Count;

                //ViewModel
                MainViewModel model = (MainViewModel) DataContext;

                //looking for the person, to whom taskList a new task should be added
                for (int i = 0; i < model.Names.Count; i++)
                {

                    if (checkedName == model.Names[i].PersonName)
                    {
                        index = model.Names[i].Id; //saving the index(Id) of the person, to whom taskList a new task should be added
                    }
                }
                //if index is not default
                if (index < App.ViewModel.Tasks.Count)
                {
                    //Adding a task  to taskList of "checked(in CheckBox)" person
                    App.ViewModel.Tasks[index].Add(new ItemViewModel()
                                                       {TaskName = EnterNameBox.Text, Category = category});
                }
                App.ViewModel.SaveData();
            }
        }

        protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
        {
            // If the session is still in progress, save it and we can resume it later.
            // TODO Save what the user has currently typed into the box

            try {
                using (var storage = IsolatedStorageFile.GetUserStoreForApplication()) {
                    // Treat the back key as exiting and not saving
                    if ((session != null && !session.IsFinished) && e.NavigationMode != NavigationMode.Back) {
                        using (var file = storage.OpenFile("Session", FileMode.Create, FileAccess.Write, FileShare.None)) {
                            using (var sw = new StreamWriter(file)) {
                                var json = session.ToJson(new JsonContext());
                                JsonValue.WriteMin(json, sw);
                            }
                        }
                    } else {
                        storage.DeleteFile("Session");
                    }
                }
            } catch (IsolatedStorageException) {
                return;
            } catch (IOException) {
                return;
            } catch (FormatException) {
                return;
            }

            base.OnNavigatingFrom(e);
        }