Afficher un toast en vue à l'aide gestionnaire d'événements dans MvvmCross Xamarin android

Question

Ce que je: J'ai un ListView RecyclerView et une fonctionnalité onClick pour elle

Ce que je suis en train: Essayer de montrer un toast en vue utilisant gestionnaire d'événements

---

MonkeysViewModel.cs

namespace ListView.Core.ViewModels 
{ 
    public class MonkeysViewModel : MvxViewModel 
    { 
     public MvxObservableCollection<Monkey> Monkeys = new MvxObservableCollection<Monkey>(); 
     private MvxCommand<Monkey> _clickFunction; 

     public MonkeysViewModel() 
     { 
      Monkey m1 = new Monkey 
      { 
       Name = "Baboon", 
       Location = "Africa & Asia", 
       Details = "Baboons are African and Arabian Old World monkeys belonging to the genus Papio, part of the subfamily Cercopithecinae.", 
       Image = "http://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Papio_anubis_%28Serengeti%2C_2009%29.jpg/200px-Papio_anubis_%28Serengeti%2C_2009%29.jpg" 
      }; 

      Monkeys.Add(m1); 

      Monkey m2 = new Monkey 
      { 
       Name = "Capuchin Monkey", 
       Location = "Central & South America", 
       Details = "The capuchin monkeys are New World monkeys of the subfamily Cebinae. Prior to 2011, the subfamily contained only a single genus, Cebus.", 
       Image = "http://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Capuchin_Costa_Rica.jpg/200px-Capuchin_Costa_Rica.jpg" 
      }; 
      Monkeys.Add(m2); 
      MonkeyList = Monkeys; 

     } 

     public MvxObservableCollection<Monkey> MonkeyList 
     { 
      get { return Monkeys; } 
      set { Monkeys = value; RaisePropertyChanged(() => MonkeyList); } 
     } 


     public IMvxCommand clickFunction 
     { 
      get { return _clickFunction ?? (_clickFunction = new MvxCommand<Monkey>(OnMemorySelected)); } 
     } 

     void OnMemorySelected(Monkey selectedMemory) 
     { 
      //Trying to display a Toast message here using event handler and trigger an event in view so I can show a toast 
     } 

    } 
} 

---

Monkey.cs

namespace ListView.Core.Models 
{ 
    public class Monkey 
    { 
     public string Name { get; set; } 
     public string Location { get; set; } 
     public string Details { get; set; } 
     //URL for our monkey image! 
     public string Image { get; set; } 
    } 
} 

---

MonkeysView.axml

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:local="http://schemas.android.com/apk/res-auto" 
    android:orientation="vertical" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:background="@android:color/holo_blue_dark"> 

    <MvvmCross.Droid.Support.V7.RecyclerView.MvxRecyclerView 
     android:id="@+id/my_recycler_view" 
     android:scrollbars="vertical" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     local:MvxItemTemplate="@layout/listitem_monkey" 
     local:MvxBind="ItemsSource MonkeyList; ItemClick clickFunction" 
     /> 


</LinearLayout> 

---

MonkeysView.cs

namespace ListView.Droid.Views 
{ 
    [Activity(Label = "ListView.Droid", MainLauncher = true, Icon = "@drawable/icon")] 
    public class MonkeysView : MvxActivity 
    { 


     protected override void OnViewModelSet() 
     { 
      base.OnViewModelSet(); 
      SetContentView(Resource.Layout.MonkeysView); 
     } 
    } 
} 

Answer 1

Voir modèle

Vous pouvez créer un EventArgs personnalisé

Ajoutez le gestionnaire d'événement à votre vue Modèle

public event EventHandler<SelectedMonkeyEventArgs> OnMonkeySelected; 

Invoquez ensuite l'événement dans le OnMemorySelected

void OnMemorySelected(Monkey selectedMemory) 
{ 
    OnMonkeySelected?.Invoke(this, new SelectedMonkeyEventArgs(selectedMemory)); 
} 

Voir

vous inscrire/désinscrire à l'événement dans votre activité

protected override void OnPause() 
{ 
    ViewModel.OnMonkeySelected -= ViewModel_OnMonkeySelected; 
    base.OnPause(); 
} 

protected override void OnResume() 
{ 
    ViewModel.OnMonkeySelected += ViewModel_OnMonkeySelected; 
    base.OnResume(); 
} 

private void ViewModel_OnMonkeySelected(object sender, GenericWebViewViewModel.SelectedMonkeyEventArgs e) 
{ 
    Toast.MakeText(this, $"Selected Monkey {e.Monkey.Name }", ToastLength.Short) 
     .Show(); 
}