void Handle_ItemSelected(object sender, Xamarin.Forms.SelectedItemChangedEventArgs e)
{
//if (e.SelectedItem == null) return;
var contact = e.SelectedItem as Contact;
var detailPage = new DetailPage(contact);
//detailPage.SliderValueChanged += DetailPage_SliderValueChanged;
MessagingCenter.Subscribe <DetailPage, int>(this, Events.SliderValueChanged, DetailPage_SliderValueChanged);
//MessagingCenter.Unsubscribe<DetailPage>(this, "SliderValueChanged");
Detail = new NavigationPage(detailPage);
IsPresented = false; //Is master presented?
//await Navigation.PushAsync(new DetailPage(contact));
//ContactListView.SelectedItem = null;
}
void DetailPage_SliderValueChanged(DetailPage sender, int e)
{
SliderLabel.Text = "Slider value: " + e;
}