更新 Xamarin.Android 中的 ListView

Question

I have a ListView Adapter and whenever i click an Item, an Alert Dialog is shown. The "Löschen" (Delete in German) Button deletes the Item in the List, but somehow the Listview is not Updated.

here is the Code where i am struggling:

    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.ArbZListe);

        ArbZList = (ListView)FindViewById<ListView>(Resource.Id.ArbZListview);
        ArbZList.Adapter = new ArrayAdapter(this, Android.Resource.Layout.SimpleListItem1, MainActivity.Arbeitstage);

        ArbZList.ItemClick += ArbZList_ItemClick;
    }

    void ArbZList_ItemClick(object s, AdapterView.ItemClickEventArgs e)
    {
        try
        {
            var t = MainActivity.Arbeitstage[e.Position];
            
            AlertDialog.Builder dialog = new AlertDialog.Builder(this);
            AlertDialog alert = dialog.Create();
            alert.SetTitle("Wollen sie den Eintrag bearbeiten?");
            alert.SetMessage(t);

            alert.SetButton("Bearbeiten", AlertBearbeitenClick);

            alert.SetButton2("Löschen", (c, dcea) =>
             {
                //Delete task
                RemoveItemAt(e.Position);
             });

            alert.Show();
        } 
        catch (ArgumentOutOfRangeException)
        {

        }
        //List should be refreshed here!
    }

I didn't even get the basic approach working (add a ListView Item)... What am i missing?

Answer 1

You could do like below through the adapter.Remove() method:

ArrayAdapter adapter;
protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);
    SetContentView(Resource.Layout.ArbZListe);

    ArbZList = (ListView)FindViewById<ListView>(Resource.Id.ArbZListview);
    adapter = new ArrayAdapter(this, Android.Resource.Layout.SimpleListItem1, MainActivity.Arbeitstage);
    ArbZList.Adapter = adapter;
    ArbZList.ItemClick += ArbZList_ItemClick;
}

 void ArbZList_ItemClick(object s, AdapterView.ItemClickEventArgs e)
{
    try
    {
        var t = MainActivity.Arbeitstage[e.Position];
        
        AlertDialog.Builder dialog = new AlertDialog.Builder(this);
        AlertDialog alert = dialog.Create();
        alert.SetTitle("Wollen sie den Eintrag bearbeiten?");
        alert.SetMessage(t);

        alert.SetButton("Bearbeiten", AlertBearbeitenClick);

        alert.SetButton2("Löschen", (c, dcea) =>
         {
            //Delete task
            adapter.Remove(t);
         });

        alert.Show();
    } 
    catch (ArgumentOutOfRangeException)
    {

    }
    //List should be refreshed here!
}