ios - 如何在 Swift 2/AVPlayer 中恢复背景音频？

Question

我正在学习 Swift 作为我的第一门编程语言。

在中断(例如通话)后，我一直在努力恢复后台音频播放

应该发生什么:

1. 当应用进入后台时音频继续播放(有效)
2. 当被来电打断时，获取打断开始的通知(作品)
3. 通话结束时，获取中断通知结束(作品)
4. 继续播放音频(不起作用 - 什么也听不到)

非常感谢任何帮助!谢谢

注意事项:

1. 该应用已注册背景音频并在中断前正常播放
2. 我试过有和没有时间延迟来恢复播放——都没有用

代码:

import UIKit
import AVFoundation

var player: AVQueuePlayer!

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        do {
            try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback)
            try AVAudioSession.sharedInstance().setActive(true, withOptions: .NotifyOthersOnDeactivation)
        } catch { }
        let songNames = ["music"]
        let songs = songNames.map { AVPlayerItem(URL:
            NSBundle.mainBundle().URLForResource($0, withExtension: "mp3")!) }
        player = AVQueuePlayer(items: songs)

        let theSession = AVAudioSession.sharedInstance()
        NSNotificationCenter.defaultCenter().addObserver(self,
            selector:"playInterrupt:",
            name:AVAudioSessionInterruptionNotification,
            object: theSession)

        player.play()
    }

    func playInterrupt(notification: NSNotification) {

        if notification.name == AVAudioSessionInterruptionNotification
            && notification.userInfo != nil {

            var info = notification.userInfo!
            var intValue: UInt = 0
            (info[AVAudioSessionInterruptionTypeKey] as! NSValue).getValue(&intValue)
            if let type = AVAudioSessionInterruptionType(rawValue: intValue) {
                switch type {
                case .Began:
                    print("aaaaarrrrgggg you stole me")
                    player.pause()

                case .Ended:
                    let timer = NSTimer.scheduledTimerWithTimeInterval(3, target: self, selector: "resumeNow:", userInfo: nil, repeats: false)
                }
            }
        }
    }
    func resumeNow(timer : NSTimer) {
        player.play()
        print("attempted restart")
    }
}

Answer 1

终于明白了!

解决方案:通过将 setCategory 行更改为添加可混合选项:

AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback,
                                            withOptions: .mixWithOthers )