Person のコレクションを保持するViewModel

MainWindowViewModel.cs

using Livet;
using Livet.Commands;
using MenuButtonApp2.Models;
using System.Collections.ObjectModel;
using System.Windows;

namespace MenuButtonApp2.ViewModels {
    public class MainWindowViewModel : ViewModel {
        public MainWindowViewModel() {
            this.Persons = new ObservableCollection<Person>();
            this.Persons.Add(new Person() {Id = 1, Name = "平本", Age = 17});
            this.Persons.Add(new Person() {Id = 2, Name = "ファウラー", Age = 51});
            this.Persons.Add(new Person() {Id = 3, Name = "ヘルスバーグ", Age = 54});
            this.Persons.Add(new Person() {Id = 4, Name = "ペゾルト", Age = 61});
            this.Persons.Add(new Person() {Id = 5, Name = "リヒター", Age = 54});
            this.Persons.Add(new Person() {Id = 6, Name = "トーバルズ", Age = 45});
            this.Persons.Add(new Person() {Id = 7, Name = "ストロヴストルップ", Age = 64});
            this.Persons.Add(new Person() {Id = 8, Name = "カーニハン", Age = 73});
            this.Persons.Add(new Person() {Id = 9, Name = "ベック", Age = 53});
        }

        #region Person変更通知プロパティ
        private Person _Person;

        public Person Person {
            get { return _Person; }
            set { 
                if (_Person == value) return;
                _Person = value;
                RaisePropertyChanged("Person");
            }
        }
        #endregion

        #region Persons変更通知プロパティ
        private ObservableCollection<Person> _Persons;

        public ObservableCollection<Person> Persons {
            get { return _Persons; }
            set { 
                if (_Persons == value) return;
                _Persons = value;
                RaisePropertyChanged("Persons");
            }
        }
        #endregion

        #region MessageCommand
        private ViewModelCommand _MessageCommand;

        public ViewModelCommand MessageCommand {
            get {
                if (_MessageCommand == null) {
                    _MessageCommand = new ViewModelCommand(Message);
                }
                return _MessageCommand;
            }
        }

        public void Message() {
            var message = new System.Text.StringBuilder();
            message.AppendFormat("名前 = {0}", this.Person.Name);
            message.AppendLine();
            message.AppendFormat("年齢= {0}", this.Person.Age);

            MessageBox.Show(message.ToString());
        }
        #endregion
    }
}