我在这里按照说明进行操作，我已经整理了这个测试项目来处理音频播放的中断。具体来说，我使用默认 iphone 时钟应用程序中的闹钟作为中断。似乎中断处理程序被调用但没有超过该let = interruptionType行，因为“错误类型”出现了两次。
import UIKit
import AVFoundation
class ViewController: UIViewController {
var player = AVAudioPlayer()
let audioPath = NSBundle.mainBundle().pathForResource("rachmaninov-romance-sixhands-alianello", ofType: "mp3")!
func handleInterruption(notification: NSNotification) {
guard let interruptionType = notification.userInfo?[AVAudioSessionInterruptionTypeKey] as? AVAudioSessionInterruptionType else { print("wrong type"); return }
switch interruptionType {
case .Began:
print("began")
// player is paused and session is inactive. need to update UI)
player.pause()
print("audio paused")
default:
print("ended")
/**/
if let option = notification.userInfo?[AVAudioSessionInterruptionOptionKey] as? AVAudioSessionInterruptionOptions where option == .ShouldResume {
// ok to resume playing, re activate session and resume playing
// need to update UI
player.play()
print("audio resumed")
}
/**/
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
do {
try player = AVAudioPlayer(contentsOfURL: NSURL(fileURLWithPath: audioPath))
player.numberOfLoops = -1 // play indefinitely
player.prepareToPlay()
//player.delegate = player
} catch {
// process error here
}
// enable play in background https://stackoverflow.com/a/30280699/1827488 but this audio still gets interrupted by alerts
do {
try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback)
print("AVAudioSession Category Playback OK")
do {
try AVAudioSession.sharedInstance().setActive(true)
print("AVAudioSession is Active")
} catch let error as NSError {
print(error.localizedDescription)
}
} catch let error as NSError {
print(error.localizedDescription)
}
// add observer to handle audio interruptions
// using 'object: nil' does not have a noticeable effect
let theSession = AVAudioSession.sharedInstance()
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(ViewController.handleInterruption(_:)), name: AVAudioSessionInterruptionNotification, object: theSession)
// start playing audio
player.play()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
此外，按照这里的想法，我将处理程序修改为
func handleInterruption(notification: NSNotification) {
//guard let interruptionType = notification.userInfo?[AVAudioSessionInterruptionTypeKey] as? AVAudioSessionInterruptionType else { print("wrong type"); return }
if notification.name != AVAudioSessionInterruptionNotification
|| notification.userInfo == nil{
return
}
var info = notification.userInfo!
var intValue: UInt = 0
(info[AVAudioSessionInterruptionTypeKey] as! NSValue).getValue(&intValue)
if let interruptionType = AVAudioSessionInterruptionType(rawValue: intValue) {
switch interruptionType {
case .Began:
print("began")
// player is paused and session is inactive. need to update UI)
player.pause()
print("audio paused")
default:
print("ended")
/** /
if let option = notification.userInfo?[AVAudioSessionInterruptionOptionKey] as? AVAudioSessionInterruptionOptions where option == .ShouldResume {
// ok to resume playing, re activate session and resume playing
// need to update UI
player.play()
print("audio resumed")
}
/ **/
player.play()
print("audio resumed")
}
}
}
结果是所有“开始”、“音频暂停”、“结束”和“音频恢复”都显示在控制台中，但实际上并未恢复音频播放。
注意：我移动了player.play()注释掉的where option == .ShouldResumeif 语句的外部，因为发生中断时该if条件不成立。.Ended