WPF: NavigationService is NULL after 2nd page visit

Question

Scenario:

I have a NavigationWindow style like this:

<Style TargetType="NavigationWindow" x:Key="{x:Type NavigationWindow}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="NavigationWindow" >
                    ...
</Style>

I start my app with loading a Page called Home.xaml. In Home.xaml I have a button that navigates to another page called PersonalData:

private void btnNewUser_Click(object sender, System.Windows.RoutedEventArgs e)
{
    PersonalData personalData = new PersonalData();
    this.NavigationService.Navigate(personalData);
}

This works fine and the PersonalData Page gets loaded. On that second Page I have a button "Home" that navigates back to the Home page:

 private void btnHome_Click(object sender, System.Windows.RoutedEventArgs e)
 {
  Home home = new Home();
  this.NavigationService.Navigate(home);
 }

I use "Navigate" here because I want to reuse that button on later forms too, to always have a button that leads to the start page.

So this also works and the Home page gets loaded. I can even click btnNewUser there a second time and again, the PersonalData page gets opened without any problems.

BUT, when I then click the "Home" button for the second time, I get an error that "this.NavigationService" is null..

I've just started with WPF and I have no idea where to start on fixing this.. Anyone?

Answer 1

I have tried your scenario and it works fine for me. Have you solved the problem or not? Could you paste the whole example?