Thread.Sleep doesn\'t seem to be supported in .NET for Windows Store apps.
For example, this
System.Threading.Thread.Sleep(1000);
MainPage.xaml.cs
public MainPage() { this.InitializeComponent(); this.WaitForFiveSeconds(); } private async void WaitForFiveSeconds() { await System.Threading.Tasks.Task.Delay(TimeSpan.FromSeconds(5)); // do something after 5 seconds! }