NotificationCenter发现问题

Question

使用swift3遇到一些问题 - ＆gt; swift4转换。这是转换前的原始代码：

NotificationCenter.default.addObserver(self, selector: #selector(DataCollectionViewController.playerItemDidReachEnd), name: Notification.Name.AVPlayerItemDidPlayToEndTime, object: carVideoPlayer?.currentItem)

_ = observe(notificationName: Notification.Name.UIApplicationDidBecomeActive) {
    _ in
    if recorder.tripRunning {
        self.carVideoPlayer?.play()
    }
}

_ = observe(notificationName: Notification.Name.UIApplicationDidEnterBackground) {
    _ in
    self.carVideoPlayer?.pause()
}
_ = observe(notificationName: .tripStopped) {
    _ in
    self.carVideoPlayer?.pause()
}

转换后，我遇到调用observe的行的语法问题; ＆＃34;通用参数＆＃39;价值＆＃39;无法推断＆＃34;。有谁知道这个的原因？ Swift 4的编译器说参数标签是无关的，闭包类型需要2个参数。 这是转换后的代码：

NotificationCenter.default.addObserver(self, selector: #selector(DataCollectionViewController.playerItemDidReachEnd), name: Notification.Name.AVPlayerItemDidPlayToEndTime, object: carVideoPlayer?.currentItem)


    _ = observe(Notification.Name.UIApplicationDidBecomeActive) {
        _,_ in
        if recorder.tripRunning {
            self.carVideoPlayer?.play()
        }
    }

    _ = observe(Notification.Name.UIApplicationDidEnterBackground) {
        _,_ in
        self.carVideoPlayer?.pause()
    }
    _ = observe(.tripStopped) {
        _,_ in
        self.carVideoPlayer?.pause()
    }