聚焦时向 UIButton 添加操作（快速）

Question

尝试在 UIButton 获得焦点时向其添加操作 (tvOS)。

我正在使用

override func didUpdateFocusInContext(context: UIFocusUpdateContext, withAnimationCoordinator coordinator: UIFocusAnimationCoordinator) {
       super.didUpdateFocusInContext(context, withAnimationCoordinator: coordinator)

然后：

    if self.button1.focused == true {
    //do something
    }

  if self.button2.focused == true {
    //do something else
    }

这是最好的方法还是我会遇到麻烦？

编辑：

您认为这是正确的还是有更好的方法？

 override func didUpdateFocusInContext(context: UIFocusUpdateContext, withAnimationCoordinator coordinator: UIFocusAnimationCoordinator) {
            super.didUpdateFocusInContext(context, withAnimationCoordinator: coordinator)
            coordinator.addCoordinatedAnimations({ () -> Void in

                var previewPlayer = AVPlayer()
                let previewPlayerLayer = AVPlayerLayer(player: previewPlayer)

                previewPlayerLayer.frame = CGRectMake(self.view.frame.size.width/2-128, self.view.frame.size.height/2-254, 254, 128)
                previewPlayer.volume = 0

                 if self.button1.focused == true {

                    let videoURL = NSURL(string: "someString")!
                    previewPlayer = AVPlayer(URL: videoURL)

                }

                if self.button2.focused == true {

                    let videoURL = NSURL(string: "someOtherString")!
                    previewPlayer = AVPlayer(URL: videoURL)

                }


                  previewPlayer.play()


                }) { () -> Void in

            }
        }

Answer 1

您可以通过以下两种方式之一了解视图何时聚焦：

//returns bool whether view is focused
someview.focused 

//returns focused view, can return nil
UIScreen.mainScreen().focusedView

这些方法中的任何一种都是正确的，不会给您带来麻烦；）