Handling back button Windows 8.1 Universal app

Question

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?

possible duplicate of [Windows Phone 8.1 Universal App terminates on navigating back from second page?](http://stackoverflow.com/questions/24335925/windows-phone-8-1-universal-app-terminates-on-navigating-back-from-second-page) — Igor Ralic, Jul 03 '14 at 16:07
@igrali HardwareButtons class isnt supported on universal apps, only Windows Phone 8. [link](http://msdn.microsoft.com/en-US/library/windowsphone/develop/windows.phone.ui.input.hardwarebuttons.aspx) that question isnt solving anything... — Nanoc, Jul 03 '14 at 16:13
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, Jul 03 '14 at 16:52
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, Jul 03 '14 at 16:57
Ok, i was thinking it will just throw an exception if i use something i cant, but it seems than i need that to access the Windows.Phone namespace, good to know it, VS force me to use full namespace or it tell me that class doesnt exists. Really thanks. — Nanoc, Jul 03 '14 at 17:14
I think you are adding blank page, add basic page and it will handle all. — Yawar, Jun 15 '15 at 10:04

score 5 · Answer 1 · answered Oct 08 '14 at 17:21

5

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;
    }

answered Oct 08 '14 at 17:21

mimipofi

655
6
6

will the statement e.Handled = true; be executed after "Frame.GoBack();" ? see http://stackoverflow.com/questions/24557713/handling-back-button-windows-8-1-universal-app – Mechanical Object Nov 23 '14 at 13:21
what about windows 8.1 soft back key? – Yawar Jun 15 '15 at 10:03
1

Won't this create a leak if the page is not cached and later recreated? Perhaps it's better to subscribe on enter and unsub on exit? – Drew Noakes Aug 22 '15 at 20:11
It's probably better to do this in `App.xaml.cs` and check `Frame.CanGoBack` first. – Drew Noakes Aug 22 '15 at 20:40

score -1 · Answer 2 · answered May 30 '16 at 09:33

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

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();
      }
   }

Handling back button Windows 8.1 Universal app

2 Answers2

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