Handling back button Windows 8.1 Universal app

3
votes

I'm updating my app from Windows Phone 8 Silverlight to Windows 8.1 RT (I think is called that).

I've just created my second page and when i go to and press the back button it goes out of my app instead of going back to first page.

I don't know why is this happening, default behaviour is going to last page right?

I can't find how to override back button event to make a Frame.GoBack() call.

Is this a dev preview bug or am I missing something?

2
windows-runtimewindows-phone-8.1win-universal-app
possible duplicate of Windows Phone 8.1 Universal App terminates on navigating back from second page? - Igor Ralic
@igrali HardwareButtons class isnt supported on universal apps, only Windows Phone 8. link that question isnt solving anything... - Nanoc
You should check your facts before saying that something is not solving anything - that link says that the minimum version is Windows Phone 8.0. My solution works for Universal Apps, and your questions is still a duplicate. - Igor Ralic
Ok i see you can make universal apps since windows 8, i was thinking was new on 8.1, anyway Visual Studio tells me that there arent any HardwareButtons class, some way to solve it? - Nanoc
Make sure it's inside #if WINDOWS_PHONE_APP - Igor Ralic

2 Answers

5
votes

put into the constructor of the second page: (SecondPage.xaml.cs)

Windows.Phone.UI.Input.HardwareButtons.BackPressed += HardwareButtons_BackPressed;

and then define the eventhandler function:

    private void HardwareButtons_BackPressed( object sender, BackPressedEventArgs e )
    {
        Frame.GoBack();
        e.Handled = true;
    }
-1
votes

In the Universal Windows Apps you can also handle "Back Button" click globally in the App.xaml.cs file. Please see below:

  1. In the OnLaunched method add below code:

    protected override void OnLaunched(LaunchActivatedEventArgs e)
{
  //..Rest of code...

   rootFrame.Navigated += OnNavigated;


    // Register a handler for BackRequested events and set the
    // visibility of the Back button:

    SystemNavigationManager.GetForCurrentView().BackRequested += OnBackRequested;

    SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility =
        rootFrame.CanGoBack  ?
        AppViewBackButtonVisibility.Visible :
        AppViewBackButtonVisibility.Collapsed;

    //..Rest of code...

}

Then you should add code for handlers methods in the App class:

    private void OnNavigated(object sender, NavigationEventArgs e)
    {
      // Each time a navigation event occurs, update the Back button's visibility:

        SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility =
        ((Frame)sender).CanGoBack ?
        AppViewBackButtonVisibility.Visible :
        AppViewBackButtonVisibility.Collapsed;
    }



   private void OnBackRequested(object sender, BackRequestedEventArgs e)
   {
      Frame rootFrame = Window.Current.Content as Frame;

      if (rootFrame.CanGoBack)
      {
        e.Handled = true;
        rootFrame.GoBack();
      }
   }