iPhone touch events for any control

I'm using the core-plot library to do some plotting, and would like t开发者_StackOverflow中文版o implement some touch control on the graph. Problem is, the core-plot graph view doesn't seem to respond to touches. I've read many places that it's possible to place an invisible control over another control and use that control to give the underlying control touch events. Problem is, I can't figure out how to implement it. Nothing seems to be working. Is there some way to specifically assign a control your own touch events and to handle them separately from the other controls? Some source code showing how this should be set up properly would be awesome.

Just a simple question before I go to sleep (it is past midnight in Europe :)). Did you try adding subview to your graph with backgroundColor = [UIColor clearColor] and attaching a UIGestureRecognizer to it?