C#, Windows Phone 7, Using if-else statement to check which page is displayed

Now I'm developing a Windows Phone 7 app, my app has three buttons located at the applicaton bar. Here is the event handler for these three buttons:

    //app bar page navigation
    private void ApplicationBarIconButton_Click1(object sender, EventArgs e)
    {
        if(//check if the current displayed page is mainpage)
        {
            //do nothing
        }
        else
        {
            NavigationService.Navigate(new Uri("/MainPage.xaml", UriKind.RelativeOrAbsolute));
        }
    }

    private void ApplicationBarIconButton_Click2(object sender, EventArgs e)
    {
        NavigationService.Navigate(new Uri("/Audios.xaml", UriKind.RelativeOrAbsolute));
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    private void ApplicationBarIconButton_Click3(object sender, EventArgs e)
    {
        NavigationService.Navigate(new Uri("/Statistics.xaml", UriKind.RelativeOrAbsolute));
    }

The button navigation works well except the first one (Button_Click1) because when I first access the main page and click the first button the app will automatically go back to app list.

So I want to use if-else statement to check which page is currently displayed and then decide whether to navigate or stay in the current page.

It looks like you are using the ApplicationBar like you would use a TabBar within iPhone (or similar in Android, Bada, etc too)

In WP7, the Metro style is typpically to use a Pivot or Panorama rather than a "Tab Bar" for this type of navigation.

If you do want to use the ApplicationBar like this:

• then you can (the WP7 Marketplace will allow it) but users might feel it's not very Metro.
• then you might want to consider disabling the appropriate button rather than just stubbing out the action.
• then you can detect the currently shown page using CurrentSource on the NavigationService

Also, please do note that if you try to navigate from MainPage.xaml to the same url MainPage.xaml then you will see an exception - as I recall, the navigation service complains about url fragments not being supported.

Button click1 should be removed from the main page. It makes no sense to have that button there.

Other pages should use the back button to return to the main page. Otherwise you mess up your back stack.