问在发送方操作方法中检测UIButton内部的点击/按下的位置

EN

@IBAction func buttonAction(sender: AnyObject, event: UIEvent) {
    // downcast sender as a UIView
    let buttonView = sender as UIView;

    // get any touch on the buttonView
    if let touch = event.touchesForView(buttonView)?.anyObject() as? UITouch {
        // print the touch location on the button
        println(touch.locationInView(buttonView))
    }
}