how to navigate to another xaml page in Windows Mobile

Question

I'm trying to go to another xaml page when listbox item in current xaml page clicked. Here is how I did.

 private void mainList_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (mainList.SelectedIndex == -1)
            return;

        NavigationService.Navigate(new Uri("/RegisterSurveyee.xaml",UriKind.Relative));
    }

but it gives me "NULLREFERENCEEXCEPTION" error. groupID groupName are not null. When I change last sentence to this.Content=new RegisterSurveyee(), it works fine. The problem occurs only at NavigationService.Navigate(new Uri("/RegisterSurveyee.xaml",UriKind.Relative)); any help???

Answer 1

i) Make sure that e.AddedItems[0] is not null and it is of type SurveyGroup

If you are getting null reference exception,

 if (mainList ==null || mainList.SelectedIndex == -1)
            return;

ii) When Navigating from one page to another, you have to give to full name including .xaml extension

 NavigationService.Navigate(new Uri("/RegisterSurveyee.xaml",UriKind.Relative));

If you are still getting NullReference Exception, try registering to the SelectionChanged Event on the Loaded event of the Page.

    private void MainPage_OnLoaded(object sender, RoutedEventArgs e)
    {
        ListBox.SelectionChanged += ListBoxSelectionChanged;
    }