ItemList MVVM Tap Command

ListView.cs

using System;
using System.Windows.Input;
using Xamarin.Forms;


namespace YourNS {

    public class ListView : Xamarin.Forms.ListView {

        public static BindableProperty ItemClickCommandProperty = BindableProperty.Create<ListView, ICommand>(x => x.ItemClickCommand, null);


        public ListView() {
            this.ItemTapped += this.OnItemTapped;
        }


        public ICommand ItemClickCommand {
            get { return (ICommand)this.GetValue(ItemClickCommandProperty); }
            set { this.SetValue(ItemClickCommandProperty, value); }
        }


        private void OnItemTapped(object sender, ItemTappedEventArgs e) {
            if (e.Item != null && this.ItemClickCommand != null && this.ItemClickCommand.CanExecute(e)) {
                this.ItemClickCommand.Execute(e.Item);
                this.SelectedItem = null;
            }
        }
    }
}

MyPage.xaml

ContentPage ...
             xmlns:local="clr-namespace:Samples.Views;assembly=Your Assebly Name">

<local:ListView ItemClickCommand="{Binding TapCommand}" 
        ItemsSource="{Binding List}">

ViewModelCase1.cs

private Command<Signature> _tapCommand;
        public Command<Signature> TapCommand {
            get {
                this._tapCommand = this._tapCommand ?? new Command<Signature>(s => 
                    this.dialogs.ActionSheet(new ActionSheetConfig()
                        .Add("View", () => {
                            if (!this.fileViewer.Open(s.FilePath))
                                this.dialogs.Alert(String.Format("Could not open file {0}", s.FileName));
                        })
                        .Add("Cancel")
                    )
                );
                return this._tapCommand;
            }
        }

ViewModelCase2.cs

 public ViewModelCase1() 
        {
            ItemList = new List<SampleModel>().ToObservableCollection();
            TapCommand = new Command((e) =>
            {
                var itemselected = e as SampleModel;
                Debug.WriteLine(e);
            });
        }