demo-xf-app-1a/MobileApp1/Views/MyStuffPage.xaml.cs

using System;
using Xamarin.Forms;

namespace MobileApp1.Views
{
    public partial class MyStuffPage : ContentPage
    {
        public MyStuffPage()
        {
            InitializeComponent();

            label1.Text = Guid.NewGuid().ToString();
        }

    }
}