Android 4 and Fragments: Listing 2

TitlesFragment class.

public class TitlesFragment : ListFragment
    {
        int _currentPlayId;
        bool _isDualPane;
        public override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
        }
        public override void OnActivityCreated(Bundle savedInstanceState)
        {
            base.OnActivityCreated(savedInstanceState);
            var adapter = new ArrayAdapter<String>(Activity, 
                Android.Resource.Layout.SimpleListItem1, StarTrek.Character);
            ListAdapter = adapter;
            if (savedInstanceState != null)
            {
                _currentPlayId = savedInstanceState.GetInt("current_play_id", 0);
            }
            var detailsFrame = Activity.FindViewById<View>(Resource.Id.details);
            _isDualPane = detailsFrame != null && detailsFrame.Visibility == ViewStates.Visible;
            if (_isDualPane)
            {
                ListView.ChoiceMode = ChoiceMode.Single;
                ShowDetails(_currentPlayId);
            }
        }
        public override void OnListItemClick(ListView l, View v, int position, long id)
        {
            ShowDetails(position);
        }
        private void ShowDetails(int playId)
        {
            _currentPlayId = playId;
            if (_isDualPane)
            {
                // We can display everything in place with fragments.
                // Have the list highlight this item and show the data.
                ListView.SetItemChecked(playId, true);
                // Check what fragment is shown, replace if needed.
                var details = FragmentManager.FindFragmentById(Resource.Id.details) as DetailsFragment;
                if (details == null || details.ShownPlayId != playId)
                {
                    // Make new fragment to show this selection.
                    details = DetailsFragment.NewInstance(playId);
                    // Execute a transaction, replacing any existing
                    // fragment with this one inside the frame.
                    var ft = FragmentManager.BeginTransaction();
                    ft.Replace(Resource.Id.details, details);
                    ft.SetTransition(FragmentTransit.EnterMask);
                    ft.Commit();
                }
            }
            else
            {
                // Otherwise we need to launch a new Activity to display
                // the dialog fragment with selected text.
                var intent = new Intent();
                intent.SetClass(Activity, typeof(DetailsActivity));
                intent.PutExtra("current_play_id", playId);
                StartActivity(intent);
            }
        }
    }

About the Author

Wallace (Wally) B. McClure has authored books on iPhone programming with Mono/Monotouch, Android programming with Mono for Android, application architecture, ADO.NET, SQL Server and AJAX. He's a Microsoft MVP, an ASPInsider and a partner at Scalable Development Inc. He maintains a blog, and can be followed on Twitter.

comments powered by Disqus

Featured

  • GitHub Copilot for Azure Gets Preview Glitches

    This reporter, recently accepted to preview GitHub Copilot for Azure, has thus far found the tool to be, well, glitchy.

  • New .NET 9 Templates for Blazor Hybrid, .NET MAUI

    Microsoft's fifth preview of .NET 9 nods at AI development while also introducing new templates for some of the more popular project types, including Blazor Hybrid and .NET MAUI.

  • What's Next for ASP.NET Core and Blazor

    Since its inception as an intriguing experiment in leveraging WebAssembly to enable dynamic web development with C#, Blazor has evolved into a mature, fully featured framework. Integral to the ASP.NET Core ecosystem, Blazor offers developers a unique combination of server-side rendering and rich client-side interactivity.

  • Nearest Centroid Classification for Numeric Data Using C#

    Here's a complete end-to-end demo of what Dr. James McCaffrey of Microsoft Research says is arguably the simplest possible classification technique.

  • .NET MAUI in VS Code Goes GA

    Visual Studio Code's .NET MAUI workload, which evolves the former Xamarin.Forms mobile-centric framework by adding support for creating desktop applications, has reached general availability.

Subscribe on YouTube