protected virtual async void BackRequested(object sender, BackRequestedEventArgs e)
{
var gb = GoBackViewModel;
if (gb != null)
{
var cancel = new CancelEventArgs();
await GoBackViewModel.GoingBack(cancel);
if (cancel.Cancel)
{
e.Handled = true;
return;
}
}
e.Handled = true;
if (Frame.CanGoBack)
{
Frame.GoBack();
}
}