Xamarin.Forms で Mvvm で ListView を作ってみた１

Model.cs

public class Ramen : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    /// <summary>
    /// シングルトンのインスタンス
    /// </summary>
    public static Ramen Instance { get; } = new Ramen();

    /// <summary>
    /// コンストラクターは隠ぺい
    /// </summary>
    private Ramen() { }

    #region プロパティ
    // ランダム選択用の配列
    private string[] _ramens = { "ramen1.png", "ramen2.png", "ramen3.png", "ramen4.png", "ramen5.png", "ramen6.png", "ramen7.png", "ramen8.png", "ramen9.png" };

    public ObservableCollection<RamenItem> Items { get; } = new ObservableCollection<RamenItem>();
    #endregion

    #region メソッド

    public void Initialize()
    {
        this.Items.Clear();
        this.Items.Insert(0, new RamenItem("Item_1", "Description_1", "ramen4.png"));
    }

    public void AddItem()
    {
        var rdm = new Random();
        this.Items.Insert(0, new RamenItem(
            "Item_" + rdm.Next(),
            "Description_" + rdm.Next(),
            _ramens[rdm.Next(0, 8)]
            ));
        // PropertyChangedイベントを発火
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Items)));
    }

    public void DeleteItem()
    {
        if (this.Items.Count > 0)
        {
            this.Items.Remove(this.Items[this.Items.Count - 1]);
            // PropertyChangedイベントを発火
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Items)));

        }
    }
    #endregion

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}