App仅在iOS 13上崩溃：“必须返回MPRemoteCommandHandlerStatus或将完成处理程序作为第二个参数。”

Question

我的代码在iOS 12及更低版本上完美运行：

fileprivate func setupRemoteControl() {

    UIApplication.shared.beginReceivingRemoteControlEvents()
    let commandCenter = MPRemoteCommandCenter.shared()
    commandCenter.playCommand.isEnabled = true
    commandCenter.playCommand.addTarget { (_) -> MPRemoteCommandHandlerStatus in
        self.player.play()
        self.playPause.setImage(#imageLiteral(resourceName: "PausePlayer"), for: .normal)
        self.miniPlayPauseButton.setImage(#imageLiteral(resourceName: "PausePlayerMini"), for: .normal)
        self.setupElapsedTime()
        MPNowPlayingInfoCenter.default().nowPlayingInfo?[MPNowPlayingInfoPropertyPlaybackRate] = 1
        return .success
    }
    commandCenter.pauseCommand.isEnabled = true
    commandCenter.pauseCommand.addTarget { (_) -> MPRemoteCommandHandlerStatus in
        self.player.pause()
        self.playPause.setImage(#imageLiteral(resourceName: "PlayPlayer"), for: .normal)
        self.miniPlayPauseButton.setImage(#imageLiteral(resourceName: "PlayPlayerMini"), for: .normal)
        self.setupElapsedTime()
        MPNowPlayingInfoCenter.default().nowPlayingInfo?[MPNowPlayingInfoPropertyPlaybackRate] = 0
        return .success
    }
    commandCenter.togglePlayPauseCommand.isEnabled = true
    commandCenter.togglePlayPauseCommand.addTarget { (_) -> MPRemoteCommandHandlerStatus in
        self.handlePlayPause()
        return .success
    }
    commandCenter.skipForwardCommand.addTarget(self, action: #selector(handleSkipForward))
    commandCenter.skipBackwardCommand.addTarget(self, action: #selector(handleSkipBackward))
}

@objc fileprivate func handleSkipForward() {
    print("Seek 15 sec forward")
    let fifteenSeconds = CMTimeMakeWithSeconds(15, Int32(NSEC_PER_SEC))
    let seekTime = CMTimeAdd(player.currentTime(), fifteenSeconds)
    let elapsedTime = CMTimeGetSeconds(seekTime)
    MPNowPlayingInfoCenter.default().nowPlayingInfo![MPNowPlayingInfoPropertyElapsedPlaybackTime] = elapsedTime
    player.seek(to: seekTime)
}

@objc fileprivate func handleSkipBackward() {
    print("Seek 15 sec backward")
    let fifteenSeconds = CMTimeMakeWithSeconds(-15, Int32(NSEC_PER_SEC))
    let seekTime = CMTimeAdd(player.currentTime(), fifteenSeconds)
    let elapsedTime = CMTimeGetSeconds(seekTime)
    MPNowPlayingInfoCenter.default().nowPlayingInfo![MPNowPlayingInfoPropertyElapsedPlaybackTime] = elapsedTime
    player.seek(to: seekTime)
}

但是，当我尝试在iOS 13模拟器上运行时，AppDelegate文件出错导致应用程序崩溃：

“线程1：异常：”不支持的操作方法签名。必须返回MPRemoteCommandHandlerStatus或采用完成处理程序作为第二个参数。“

怎么了？

Answer 1