How do I make a sound hold for a long time?

Question

I'm making a music app with a piano, but I need to be able to hold the sound long or short. So like if I hold a button it will start playing the sound but if I let go it stops WITH A FADE, so however long I hold the button down that is how long the sound will play (that is until the sound ends).

How do I do this in the iPhone SDK?

Answer 1

UIButton is a subclass of UIResponder, which has methods to tell it when a touch begins or ends - making use of those should get you what you need.