Xamarin.Forms中的导航不起作用

Question

The navigation doesn't work by setting the Mainpage as the navigation page or by setting the Mainpage to be another content page as i tried the solution Here: How to navigate one Content page to another Content page from client project (IOS/Android) in xamarin forms?

using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;

namespace App14
{
public partial class MainPage : ContentPage
{
    public MainPage()
    {
        InitializeComponent();
        Application.Current.MainPage = new Page1();


    }


}
}

If I run the above code i don't see any Content The app just load and terminates

    using System;
        using System.Collections.Generic;
        using System.Linq;
        using System.Text;
    using System.Threading.Tasks;
   using Xamarin.Forms;

   namespace App14
   {
   public partial class MainPage : ContentPage
  {
    public MainPage()
     {
        InitializeComponent();
        App.Current.MainPage = new NavigationPage();
        Application.Current.MainPage.Navigation.PushAsync(new Page1())




    }


}
 }

and if tried making the MainPage a navigation Page and Pushasync code it won't work either

Answer 1

Your App.xaml.cs , which inherits from Application should be loading your MainPage and for navigation, it should be wrapped in a NavigationPage .

public partial class App : Application
{
    public App()
    {
        InitializeComponent();

        var navigationPage = new NavigationPage(new MainPage());
        MainPage = navigationPage;
    }

    ...
}

Answer 2

Looks like you want to lauch your app having its root page to be Page1 .

If this is true then you are writing navigation logic at a wrong place. You should remove navigation logic from your MainPage's constructor and write your first page navigation into App.cs class as follows:

public partial class App : Application
{
    public App ()
    {
        InitializeComponent ();
        MainPage = new NavigationPage(new Page1 ());
    }
}

Otherwise ,

If you want to launch your app with having MainPage as your root page and then immediately want to push Page1 onto navigation stack then:

public partial class App : Application
{
    public App ()
    {
        InitializeComponent ();

        var navPage = new NavigationPage(new App14.MainPage()); 
        Application.Current.MainPage = navPage; 

        navPage.PushAsync(new Page1());
    }
}

For more detail on navigation in Xamarin.Forms click here .