public ItemsViewModel() { Title = "Browse"; Notes = new ObservableCollection <Note>(); LoadItemsCommand = new Command(async() => await ExecuteLoadItemsCommand()); //Handle "SaveNote" message MessagingCenter.Subscribe <ItemDetailPage, Note>(this, "SaveNote", async(sender, note) => { Notes.Add(note); await MockDataStore.AddNoteAsync(note); }); //Handle "UpdateNote" message MessagingCenter.Subscribe <ItemDetailPage, Note>(this, "UpdateNote", async(sender, note) => { await MockDataStore.UpdateNoteAsync(note); await ExecuteLoadItemsCommand(); }); }