Button event for while clicked

I'd like to know if there is an event for the press/hold of a button, which is called on a press, and not after the press is released? Clicked event only works after the press is released, and the tap GestureRecognizers don't seem to be called on a tap:

    this.ClickableOverlayButton.GestureRecognizers.Add(tap);
     void tap_Tapped(object sender, EventArgs e)
         {
                throw new NotImplementedException();
         }

Thanks for any advice.