Xamarin.Forms removing a page - xamarin

Question

When my app first starts up I have it display a login page. In the login button if they are able to login I want to then remove the login page and navigate to a tabbed page. In this tabbed page I'll have a settings page that would allow me to get back to the login page if needed. Right now I have the following but it doesn't work. The HomePage is shown but the back arrow to the login page shows up and I don't want that.
public class LoginPage: ContentPage
{
public LoginPage() { // create controls here }
public btnLogin_Clicked(object sender, EventArgs e){
Navigation.PopAsync(); // remove this page (doesn't work)
Navigation.PushAsync(new HomePage());
}
}
public class App : Application
{
public App()
{
MainPage = new NavigationPage(new LoginPage());
}
}

Answer 1

Xamarin.Forms 1.3 added the capability to add and remove pages resetting the root of the navigation stack as you suggest. Your code indicates that you are using at least version 1.3. However, calling PopAsync() right off the bat is not the method you want to use as it will not pop off a page if it is the only page in the stack. Instead use the INavigation interface's InsertPageBefore(newPage, pageToPutBefore) method first and then pop the login page off the end of the stack.
You can try code similar to this:
public async void btnLogin_Clicked(object sender, EventArgs e)
{
// Do some login logic and if successful ...
Navigation.InsertPageBefore(new HomePage(), this);
await Navigation.PopAsync().ConfigureAwait(false);
}
There are several new methods in Xamarin.Forms 1.3 that substantially improve the navigation capabilities. Another possible solution to the above problem would be to first add the HomePage to the end of the stack and then use the new RemovePage method to remove the login page from the start of the stack leaving the HomePage as the only page left. One thing you want to be careful of, if you are adding the new page using an asynchronous method like PushAsync you will need to await to call to ensure the new page is finished being added to the stack before removing the old page.

Answer 2

Yet another solution: Change MainPage property
in App.cs Constructor:
public App()
{
MainPage = new LoginPage();
}
in your Login method:
Device.BeginInvokeOnMainThread(() =>
{
Application.Current.MainPage = new NavigationPage(new HomePage());
});

Answer 3

For your second point , the back arrow to the login page shows up and you don't want that >>
Use this NavigationPage.SetHasBackButton(YourPage, false);
This will remove the Back Button from your navigation bar
As an example for your code above,
HomePage myHomePage = new HomePage();
NavigationPage.SetHasNavigationBar(myHomePage , false);
Navigation.PushAsync(myHomePage);
You can explore more methods of NavigationPage - such as SetHasNavigationBar and many more, they are really good.
Please let me know if this helps.