CODEWITHSUNDEEP
androidxamarinandroid-listfragment
Marcin Zdunek
Marcin Zdunek

Reputation: 1011

Xamarin Android: update ListFragment's items periodically

here is my code:

public class ClientsFragment : ListFragment
{
    List<ClientViewModel> list;
    Timer timer;

    public override async void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        await LoadClientList();
        ListAdapter = new ClientAdapter(Activity, list);

        timer = new Timer(5000);
        timer.Elapsed += Timer_Elapsed;
        timer.Enabled = true;
    }

    private async void Timer_Elapsed(object sender, ElapsedEventArgs e)
    {
        await LoadClientList();
    }

    public async Task LoadClientList()
    {
        list = await ClientViewModel.GetAllClients();
    }
}

Everything works fine, except updating content. I have read, that NotifyDataSetChanged function is needed, but I don't know how to implement that, because every example found on web was connected with Activity or custom ListView, not ListFragment. I don't know if my timer is well-written too. Thanks for help

EDIT:

Solution was to use Activity.RunOnUiThread(() => { ListAdapter = new ClientAdapter(Activity, list); }); in the bottom of LoadClientList method.

Upvotes: 0

Views: 391

Answers (1)

Jon Douglas
Jon Douglas

Reputation: 13176

Basically if you want to reset the content in your fragment, you will need to re-attach your adapter in your scenario.

Ideally you would call NotifyDataSetChanged once you do something to the Adapter such as Add(), Remove(), Insert(), Clear(), etc.

So there's a few ways you can approach this:

  1. Simply re-create the Adapter with the new list that contains the updated list.

  2. Within your Custom Adapter, simply allow yourself to change the List inside which might call to re-attach the Adapter or call NotifyDataSetChanged using the respective methods above.

Note: You may want to ensure you are calling NotifyDataSetChanged on the UI thread.

Upvotes: 1

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