How can I know that my app gets in background.

Question

Hello,

Is there any way to know when user move away from my app. I need to stop some services when it navigate away from it.

Thanks in advance.

Answer 1

Hi Zee,

you can use the VisibilityChanged-Event for that.

Find more here: http://msdn.microsoft.com/en-us/library/windows/apps/hh464925.aspx

---

Thomas Claudius Huber

"If you can't make your app run faster, make it at least look & feel extremly fast"

My latest app: The "Womanizer" :-)
twitter: @thomasclaudiush
homepage: www.thomasclaudiushuber.com
author of: ultimate Windows Store Apps handbook | ultimate WPF handbook | ultimate Silverlight handbook

Answer 2

Hi Thomas

Thanks for your reply,

I already tried that code in App.xaml.cs but it is throwing ComException when app gets loaded. Here is the code.

public App()
{
   this.InitializeComponent();
   this.Suspending += OnSuspending;  


     Window.Current.VisibilityChanged += (s, e) =>
     {
        if (!e.Visible)
       {
          // Application went to background
       }
       else
       {
          // Application is FullScreen again
       }
     };     
}

Answer 3

Hi Zee,

place it in the OnLaunched-Method in the App.xaml before the Window.Current.Activate()-method is called:

  public App()
        {
            this.InitializeComponent();
            this.Suspending += OnSuspending;

          

        }

        /// <summary>
        /// Invoked when the application is launched normally by the end user.  Other entry points
        /// will be used such as when the application is launched to open a specific file.
        /// </summary>
        /// <param name="e">Details about the launch request and process.</param>
        protected override void OnLaunched(LaunchActivatedEventArgs e)
        {

#if DEBUG
            if (System.Diagnostics.Debugger.IsAttached)
            {
                this.DebugSettings.EnableFrameRateCounter = true;
            }
#endif

            Frame rootFrame = Window.Current.Content as Frame;

            // Do not repeat app initialization when the Window already has content,
            // just ensure that the window is active
            if (rootFrame == null)
            {
                // Create a Frame to act as the navigation context and navigate to the first page
                rootFrame = new Frame();
                // Set the default language
                rootFrame.Language = Windows.Globalization.ApplicationLanguages.Languages[0];

                rootFrame.NavigationFailed += OnNavigationFailed;

                if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
                {
                    //TODO: Load state from previously suspended application
                }

                // Place the frame in the current Window
                Window.Current.Content = rootFrame;
            }

            if (rootFrame.Content == null)
            {
                // When the navigation stack isn't restored navigate to the first page,
                // configuring the new page by passing required information as a navigation
                // parameter
                rootFrame.Navigate(typeof(MainPage), e.Arguments);
            }

            Window.Current.VisibilityChanged += (s, args) =>
            {
                if (!args.Visible)
                {
                    // Application went to background
                }
                else
                {
                    // Application is FullScreen again
                }
            };     

            // Ensure the current window is active
            Window.Current.Activate();
        }

---

Thomas Claudius Huber

"If you can't make your app run faster, make it at least look & feel extremly fast"

My latest app: The "Womanizer" :-)
twitter: @thomasclaudiush
homepage: www.thomasclaudiushuber.com
author of: ultimate Windows Store Apps handbook | ultimate WPF handbook | ultimate Silverlight handbook