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tldr: How can I replace fragments in viewpager using MvvmCross?

I have tried to replace a fragment in a viewpager using the approach described at How to replace fragments within a Viewpager. The idea is that within the view pager a "RootFragment" is shown. However, it is replaced by a first fragment. If needed, it can also be replaced by a second fragment, third fragment and so on. As more fragments are added, they are added to the backstack as well.

So this would be a snippet of the code for the "RootFragment"

public class RootView : MvxFragment

    {

        public override void OnCreate(Bundle savedInstanceState)

        {

            base.OnCreate(savedInstanceState);

        }



    public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)

    {

        var view = inflater.Inflate(Resource.Layout.root_fragment, container, false);



        var transaction = FragmentManager.BeginTransaction();

        var fragment = FirstView.NewInstance();

        transaction.Replace(Resource.Id.root_frame, fragment);



        transaction.Commit();



        return view;

    }





}

Then, a snippet for the "First fragment" would be

[MvxFragmentPresentation(typeof(MainViewModel), 

Resource.Id.root_frame, true)]

    public class ScoringView : MvxFragment<FirstViewModel>

    {

        public override void OnCreate(Bundle savedInstanceState)

        {

            base.OnCreate(savedInstanceState);



            // Create your fragment here

        }



        public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)

        {

            base.OnCreateView(inflater, container, savedInstanceState);

            return this.BindingInflate(Resource.Layout.first_fragment, null);

        }



    }

The layout for "RootFragment" is:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:background="#000"

    android:layout_height="match_parent"

    android:id="@+id/root_frame" />

The code for "FirstViewModel" would be:

public class FirstViewModel: MvxViewModel

    {

        private IMvxAsyncCommand _openPreguntasCommand;

        private IMvxNavigationService _navigationService;



        public IMvxAsyncCommand OpenSecondCommand { get => _openSecondCommand?? (new MvxAsyncCommand(async () =>

                                                                  {

                                                                      await _navigationService

                                                                          .Navigate<SecondViewModel>();

                                                                  }));  }



        public FirstViewModel(IMvxNavigationService navigationService)

        {

            _navigationService = navigationService;

        }





    }

I have tried to accomplish this task using a PresentationHint. I modified the code used in How to clear entire Backstack using viewmodel(navigation service) to suit my needs to no avail. So perhaps a custom presenter could be an option. I could override one "OnBeforeFragmentChanging" or some other related method. What I ended up doing was that used the MvxFragmentPresentation attribute and I set the fragmentContentId to the Id of the placeholder in the "RootFragment" layout. However, it seems to me that there has to be a better way.

 [MvxFragmentPresentation(typeof(MainViewModel), Resource.Id.root_frame, true)] 

Did you try the Playground example that comes with the MvvmCross source code? There is a good implementation of fragments