PushAsync is not supported globally on Android, please use a NavigationPage - Xamarin.Forms

Question

I have the following method in an Xamarin.Forms.ContentPage wired to a button click event

public class LoginPage : ContentPage
{
    private Button _loginButton = null;
    private Entry _PasswordInput = null;
    private Entry _UsernameInput = null;

    public LoginPage()
    {
        _UsernameInput = new Entry { Placeholder = "Username" };
        _PasswordInput = new Entry { Placeholder = "Password", IsPassword = true };

        _loginButton = new Button
        {
            Text = "Login",
            BorderRadius = 5
        }

        _loginButton.Clicked += LogIn;

        Content = new StackLayout 
        {
            VerticalOptions = LayoutOptions.Center,
            Children = 
            {
                 _UsernameInput, _PasswordInput, _loginButton, 
            },
            Spacing = 15
        };
    }

    public async void LogIn(object sender, EventArgs eventsArgs)
    {
        //do authenticate stuff here
        SSO.MyAuthentication client = new SSO.MyAuthentication();

        bool isAuthenticated = client.Authenticate(_UsernameInput.Text, _PasswordInput.Text);

        if(isAuthenticated)
        {
             //Push home page to top of navigation stack
             Navigation.PushAsync(new HomePage());
        }
    }
}

On the following line of code Navigation.PushAsync(new HomePage());, I am getting the following exception while debugging:

PushAsync is not supported globally on Android, please use a NavigationPage

How do I resolve this issue using a Xamarin.Forms.NavigationPage object?

Solution 1

You are calling "PushAsync":

public partial class MainPage : ContentPage
{
    public MainPage()
    {
        InitializeComponent();
    }

    private void btnCourseList_Clicked(object sender, EventArgs e)
    {
        Navigation.PushAsync(new PageB());
    }
}

but you did not start the NavigationPage, which normally is done in the App.cs class, or at least it should be started before any call to "PushAsync":

MainPage = new NavigationPage(new PageA());

Solution 2

In app.xaml.cs file,

Replace

 MainPage = new <namespace>.MainPage();

With

 MainPage = new NavigationPage(new <namespace>.MainPage());

Then Use

 await Navigation.PushAsync(new NavigationPage(new MainPage2()));

Solution 3

You need to enclose your LoginPage in a NavigationPage. This will fix your error, but will leave you with the LoginPage contained on your navigation stack.

An alternate approach would be to make your HomePage the root of the application, then display the LoginPage modally on top of it. Only when the user successfully logs in do you dismiss the LoginPage modal so they can see the HomePage.

Solution 4

First make setting in "Main App Page" then do in "Content page" to go other page:

Solution 5

I only change pushAsync with pushModalAsync :)

public async void LogIn(object sender, EventArgs eventsArgs)
{
    //do authenticate stuff here
    SSO.MyAuthentication client = new SSO.MyAuthentication();

    bool isAuthenticated = client.Authenticate(_UsernameInput.Text, _PasswordInput.Text);

    if(isAuthenticated)
    {
         //Push home page to top of navigation stack
         //Navigation.PushAsync(new HomePage());
           Navigation.PushModalAsync(new HomePage());
    }
}

View more solutions

Comments

[Michael Kniskern]

Would I enclose my LoginPage within a NavigationPage in my App.GetMainPage method? Also, could I use the 'Navigation.PopAsync()' method to remove the loginpage from the navigation stack?

[Jason]

Yes, you make NavPage your outermost page. I don't think you can use PopAsync() when there is only one page on the stack, but I haven't tried it.

[Stephane Delcroix]

Other approach is to have the LoginPage as main page for the application, and PushModalAsync a new NavigationPage with the content of the app on successful login.

[Chase Florell]

The best approach is to load the app normally and PushModalAsync() the login page. Just be sure to prevent the user from pressing the hardware back button on Android. public override void OnBackPressed(){ if(user.IsAuthenticated(){base.OnBackPressed();}}

[Alessandro Caliaro]

I have the same problem when I try to call PushAsync in a Modal Page. Something like - PushAsync - PushModalAsync - PushAsync (here I have the problem and your workarounds does not work)

[Anwar]

Tryied everthing in vain, this worked like a charm (build Android 6, emulated on LG G2 Android 4.4).

[hamdanjz4]

I preferred to use this approach instead of using some "isLoggedIn" logic in App.cs to show MainPage or LoginPage

[Muhammad Ramzan]

Thanks @Reader Man San

[GummyBear21]

Work like a charm. Thanks

[Eldlabs]

You don't need to use new NaigationPage() inside PushAsync. You can have await Navigation.PushAsync(new MainPage2()); A bit less code :)

[Shweta Nandha]

MainPage = new NavigationPage(new PageA()); working with App but not working with ContentPage

[Shweta Nandha]

await Navigation.PushAsync(new MainPage()); not working with ContentPage i am getting System.InvalidOperationException: PushAsync is not supported globally on Android, please use a NavigationPage.

[Ola Ström]

This mess up the design since it adds an navigation bar in the top of the page.

[Ola Ström]

This mess up the design since it adds an navigation bar in the top of the page.

[quemeful]

someone should make an IDE that pairs error warnings with top voted StackOverflow answers

[abhi]

The Navigation Bar is what our users desire to see. :)

[abhi]

PushModalAsync works, but it also gets rid of the Navigation bar at the top, that our users want to see.