b57965

fixed page.cs

public partial class MainPage : ContentPage
{
    Entry entry;
    StackLayout stacklayout;
    Button nextpage;

    public MainPage()
    {
        InitializeComponent();
        entry = new Entry();

        stacklayout = new StackLayout();

        nextpage = new Button() { Text="Next Page"};
        nextpage.Clicked += Nextpage_Clicked;

        stacklayout.Children.Add(nextpage);

        this.Content = stacklayout;
    }

    protected override void OnAppearing()
    {
        base.OnAppearing();

        stacklayout.Children.Insert(0, entry);
    }

    private void Nextpage_Clicked(object sender, EventArgs e)
    {
        SecondPage secondpage = new SecondPage(entry);

        Navigation.PushAsync(secondpage);
    }
}