void AddSomeGesturesUsingCode()
{
//2 options:
//1. use the standard xamarin api. e.g. view.GestureRecgonizers.Add(yourgesturerecognizer)
// and then call view.ProcessGestures();
// this has the benefit that when Xamarin add an api hook we can remove the view.ProcessGestures call and
// it will all be good.
//2. use the extension method view.AddGestureRecognizer(yourgesturerecognizer)
// this is easier to use; and does everything under the hood; but it's a bit more obtrusive.
// in all cases, until Xamarin do more to open up the api, you must use the view extension method
// removeGestureRecognizer
// comment on https://bugzilla.xamarin.com/show_bug.cgi?id=30467 to get Xamarin to expand
// IGestureRecognizer with some add/remove hooks
_stackPanRecognizer = new PanGestureRecognizer();
_stackPanRecognizer.OnAction += OnAction;
MyStack.AddGestureRecognizer(_stackPanRecognizer);
}