如何在背景Swift中播放音频？

Question

如您所见，我正在流式传输音频广播。但是当我按下主页按钮并退出应用程序时，流媒体播放停止，或者我听不到声音。如何继续在后台流式传输并从锁定屏幕收听？ViewController.Swiftimport UIKitimport AVFoundationimport MediaPlayerimport GoogleMobileAds    class ViewController: UIViewController, GADInterstitialDelegate {        @IBOutlet weak var exitMapButton: UIButton!        @IBOutlet weak var radarMap: UIWebView!        var interstitial: GADInterstitial!        func createAndLoadInterstitial() -> GADInterstitial {            var interstitial = GADInterstitial(adUnitID: "ca-app-pub-5378899862041789/2782958552")            interstitial.delegate = self            interstitial.loadRequest(GADRequest())            return interstitial        }        func getAd(){            if (self.interstitial.isReady)            {                self.interstitial.presentFromRootViewController(self)                self.interstitial = self.createAndLoadInterstitial()            }        }        @IBOutlet weak var ataturkButton: UIButton!        @IBOutlet weak var sabihaButton: UIButton!        @IBOutlet weak var esenbogaButton: UIButton!        @IBOutlet weak var weatherButton: UIButton!        @IBOutlet weak var statusLabel: UILabel!        @IBOutlet weak var playButton: UIButton!        @IBOutlet weak var webViewButton: UIButton!        var googleBannerView: GADBannerView!override func viewDidLoad() {            super.viewDidLoad()        }class PlayerAv {            var audioLink: String?            var player: AVPlayer            init(link: String) {                self.audioLink = link                self.player = AVPlayer(URL: NSURL(string: link))            }        }        var myPlayer = PlayerAv(link: "http://www.liveatc.net/play/ltba.pls")        var setTowerState = ""        @IBAction func sliderValueChanged(sender: UISlider) {            var currentValue = Float(sender.value)            println(currentValue)            myPlayer.player.volume = currentValue        } 

Answer 1

您需要设置应用程序功能后台模式（音频和AirPlay），并将AVAudioSession类别设置为AVAudioSessionCategoryPlayback并将其设置为活动状态

从Xcode 8.2.1•Swift 3.0.2开始

do {

    try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback, with: .mixWithOthers)

    print("Playback OK")

    try AVAudioSession.sharedInstance().setActive(true)

    print("Session is Active")

} catch {

    print(error)

}

Xcode 10•Swift 4.2

do {

    try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default, options: [.mixWithOthers, .allowAirPlay])

    print("Playback OK")

    try AVAudioSession.sharedInstance().setActive(true)

    print("Session is Active")

} catch {

    print(error)

}

Answer 2

Xcode 10.2.1 Swift 4

请在您的AppDelegate中添加以下代码

func application(_ application: UIApplication, willFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {

        do {

            try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback, mode: AVAudioSessionModeDefault, options: [.mixWithOthers, .allowAirPlay])

            print("Playback OK")

            try AVAudioSession.sharedInstance().setActive(true)

            print("Session is Active")

        } catch {

            print(error)

        }

        return true

    }

注意：-请根据需要配置选项。例如在播放视频文件时停止背景音频

 options: [.allowAirPlay, .defaultToSpeaker]

并且不要忘记在后台模式下启用音频和播放