OnNavigatedto Looping Error (cant go back)

Question

Hi Everyone,

Just starting to make an app, and having some issues with the OnNavigatedTo function....

Whats supposed to happen is when i click on the button to launch the page, it should automatically redirect the page to a pdf file on the internet.

When I press back, it should take me back to the main page.

Whats happening is when I click back, it takes me briefly to the redirection page, then reloads the pdf file.

I know I've done something silly here, please help and explain where I went wrong?

 public partial class Page2 : PhoneApplicationPage
    {
        public Page2()
        {
            InitializeComponent();
        }

        protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
        {
            base.OnNavigatedTo(e);

            WebBrowserTask task = new WebBrowserTask() { URL ="http://testpage.com/test/test.pdf"};
            task.Show();

        }
        protected override void OnBackKeyPress(System.ComponentModel.CancelEventArgs e)
        {
            e.Cancel = true;
            NavigationService.Navigate(new Uri("/MainPage.xaml", UriKind.Relative));
        }

    }
}

Answer 1

Hello,

My advise would be to not use a Page just to redirect to a Web page. You should put the WebBrowserTask in the Tap/Click event of the parent page.

If you really want to keep the page2 workflow, you must add a condition statement in the OnNavigatedTo in order to distinguish common navigation to the page and the back navigation:

if (e.NavigationMode == System.Windows.Navigation.NavigationMode.Back)
{
	NavigationService.GoBack(); // Go back to the previous page MainPage.xaml
}
else
{
	base.OnNavigatedTo(e);
	WebBrowserTask task = new WebBrowserTask() { URL ="http://testpage.com/test/test.pdf"};
	task.Show();
}

Hope this helps