tvOS: pressesEnded is called intermittently

问题

I am creating a subclass of a UIButton, the reason why I'm trying to intercept the touch is because I cant seem to find another way to receive 'press up' or 'press ended' events for the standard UIButton in tvOS. If I could find a way to do that then I wouldn't need to bother with the solution below.

pressesEnded(_ presses: Set<UIPress>, with event: UIPressesEvent?) doesn't seem to be getting called every time I release the 'select' button on the Apple TV Remote.

pressesBegan(_ presses: Set<UIPress>, with event: UIPressesEvent?) is being called every time without any issues. I've attached my code below. Any ideas what could be causing this issue?

class EVLPTZButton: UIButton
{
  var command: PTZCommand!
  var delegate: EVLPTZButtonCommandDelegate?

  override func pressesBegan(_ presses: Set<UIPress>, with event: UIPressesEvent?)
  {
    super.pressesBegan(presses, with: event)

    delegate?.ptzButton(pressesBeganFor: self, with: command)
  }

  override func pressesEnded(_ presses: Set<UIPress>, with event: UIPressesEvent?)
  {
    super.pressesEnded(presses, with: event)

    delegate?.ptzButton(pressesEndedFor: self)
  }
}

回答1:

After some more testing it seems that when the 'select' button is released tvOS calls either pressesEnded(_ presses: Set<UIPress>, with event: UIPressesEvent?) OR pressesCancelled(_ presses: Set<UIPress>, with event: UIPressesEvent?).

I found this solution by jumping to the definition of pressesEnded(_ presses: Set<UIPress>, with event: UIPressesEvent?) and finding this comment:

Your responder will receive either pressesEnded:withEvent or pressesCancelled:withEvent: for each press it is handling (those presses it received in pressesBegan:withEvent:).

来源：https://stackoverflow.com/questions/47307963/tvos-pressesended-is-called-intermittently