MetaProgrammingMainPageViewModel.cs

public class MainPageViewModel

    {

        [DefaultValue("")]

        public string Name { get; set; } 

        public string WelcomeMsg => $"Hello {Name}";

        public ICommand Command { get; }



        public MainPageViewModel()

        {

            Command = new Command(() => {Name="Test" }, () => Name.Length > 3);

        }



    }