event.touchesForView（）。AnyObject（）在Xcode 6.3中不起作用

This worked perfectly before:

这之前完美无缺:

func doSomethingOnDrag(sender: UIButton, event: UIEvent) {
    let touch = event.touchesForView(sender).AnyObject() as UITouch
    let location = touch.locationInView(sender)
}
func