public AstronomyMasterDetailPage()
{
var master = new AstronomyMasterPage();
if (Device.RuntimePlatform == Device.iOS)
{
master.IconImageSource = ImageSource.FromFile("nav-menu-icon.png");
}
this.Master = master;
this.MasterBehavior = MasterBehavior.Popover;
this.Detail = new NavigationPage(new AboutPage());
}
}