Xamarin white screen in local machine - xamarin

Question

enter image description here
Hello,
I have a problem with Xamarin, when i run program i see only white screen, just like on picture.
MainPage.xaml.cs have this code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Xamarin.Forms;
namespace Hello
{
public class App : Application
{
public App()
{ // The root page of your application
MainPage = new ContentPage
{
Content = new StackLayout
{
VerticalOptions = LayoutOptions.Center,
Children = {
new Label {
HorizontalTextAlignment = TextAlignment.Center,
Text = "Welcome to Xamarin Forms!"
}
}
}
};
}
protected override void OnStart()
{
// Handle when your app starts
}
protected override void OnSleep()
{
// Handle when your app sleeps
}
protected override void OnResume()
{
// Handle when your app resumes
}
}
}
I take this code from "Creating Mobile Apps with Xamarin Forms", somebody know what is wrong with this program?

Answer 1

Write your code in Shared project's App.xaml.cs class which is partial class. The code above you are showing is not partial class. Probably, as your screenshot showing you have written App class code in Main.axml.cs file
using System;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
[assembly: XamlCompilation(XamlCompilationOptions.Compile)]
namespace App
{
public partial class App : Application
{
public App()
{
InitializeComponent();
//MainPage = new MainPage();
MainPage = new ContentPage
{
Content = new StackLayout
{
VerticalOptions = LayoutOptions.Center,
Children =
{
new Label
{
HorizontalTextAlignment=TextAlignment.Center,
Text="Welcome to xamarin forms"
}
}
}
};
}
}
}