4
我正在按照說明here，我把這個測試項目放在一起來處理音頻播放的中斷。具體來說，我使用默認iPhone時鐘應用中的鬧鐘作爲中斷。看起來中斷處理程序正在調用，但沒有越過let = interruptionType行，因爲「錯誤類型」出現了兩次。如何在Swift中斷後恢復音頻？
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，下面的想法here，我已經修改了處理程序
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")
}
}
}
結果是，所有的「開始」，「音頻暫停」，「結束」和「音頻恢復」秀在控制檯中，但音頻播放實際上並沒有恢復。
注意：我在where option == .ShouldResume if語句之外移動player.play()，因爲if條件在.Ended中斷髮生時不成立。
道歉，我做這已得到糾正口誤。中斷處理程序正在調用。 – rockhammer
好吧，這將是我第一次把東西放在那裏，所以它可能會花費我幾分鐘的時間...請繼續關注 – rockhammer
感謝您對CW回答的編輯！如果您想自己轉發整個答案，我很樂意刪除CW版本，並讚揚你的努力。 – halfer