我正在使用以下代码在iOS Swift应用中录制5秒的声音样本。该代码可以很好地进行录音，并且如果插入了耳机也可以正确识别。但是，如果在录音过程中添加或卸下了耳机，录音将会中断。我不知道为什么会这样平稳运行？
import AVFoundation
class RecorderViewController: UIViewController {
var recorder: AVAudioRecorder!
var uploadObjectSuccess = false
@IBOutlet weak var recordButton: UIButton!
@IBOutlet weak var statusLabel: UILabel!
@IBOutlet weak var progressView: UIProgressView!
var meterTimer: Timer!
var soundFileURL: URL!
override func viewDidLoad() {
super.viewDidLoad()
setSessionPlayback()
askForNotifications()
checkHeadphones()
}
func updateAudioMeter(_ timer:Timer) {
self.progressView.setProgress(0, animated: false)
if recorder != nil && recorder.isRecording {
let sec = Int(recorder.currentTime.truncatingRemainder(dividingBy: 60))
let s = String(format: "%02d", sec)
statusLabel.text = s
recorder.updateMeters()
self.progressView.setProgress(Float(sec*4), animated: true)
if (sec==6) && recorder != nil {
func aux()->Bool {
recorder.stop()
return true
}
if aux()==true {
if self.soundFileURL != nil {
self.uploadObjectSuccess = false
let path = Auth.auth().currentUser?.uid
let FIRStoragePath = Storage.storage().reference().child(path!).child(FileName!)
let uploadObject = FIRStoragePath.putFile(from: self.soundFileURL!, metadata: nil)
uploadObject.observe(.success) { snapshot in
// Upload completed successfully
self.uploadObjectSuccess = true
}
uploadObject.observe(.failure) { snapshot in
// Upload failed
self.uploadObjectSuccess = true
}
}
}
}
} else if (uploadObjectSuccess==true) {
self.statusLabel.text = "00"
self.recordButton.isEnabled = true
isPlaying = false
self.uploadObjectSuccess = false
} else {
self.statusLabel.text = "00"
}
}
@IBAction func record(_ sender: Any) {
if recorder != nil {
recorder.stop()
}
recordButton.isEnabled = false
recordWithPermission(true)
}
func setupRecorder() {
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
self.soundFileURL = documentsDirectory.appendingPathComponent(self.currentFileName) //appendingPathComponent(currentFileName)
if FileManager.default.fileExists(atPath: soundFileURL.absoluteString) {
do {
try FileManager.default.removeItem(atPath: self.soundFileURL.absoluteString)
} catch let error as NSError {
print("Ooops! Something went wrong: \(error)")
}
}
let recordSettings:[String : AnyObject] = [
AVFormatIDKey: NSNumber(value:(kAudioFormatMPEG4AAC)),
AVEncoderAudioQualityKey : NSNumber(value:AVAudioQuality.min.rawValue),
//AVEncoderBitRateKey : NSNumber(value:16),
AVNumberOfChannelsKey: NSNumber(value:1),
AVSampleRateKey : NSNumber(value:16000.0)
]
do {
recorder = try AVAudioRecorder(url: soundFileURL, settings: recordSettings)
recorder.delegate = self
recorder.isMeteringEnabled = true
recorder.prepareToRecord() // creates/overwrites the file at soundFileURL
} catch let error as NSError {
recorder = nil
print(error.localizedDescription)
}
}
func recordWithPermission(_ setup:Bool) {
checkHeadphones()
setSessionPlayback()
askForNotifications()
let session:AVAudioSession = AVAudioSession.sharedInstance()
// ios 8 and later
if (session.responds(to: #selector(AVAudioSession.requestRecordPermission(_:)))) {
AVAudioSession.sharedInstance().requestRecordPermission({(granted: Bool)-> Void in
if granted {
print("Permission to record granted")
self.setSessionPlayAndRecord()
if setup {
self.setupRecorder()
}
self.recorder.record()
self.meterTimer = Timer.scheduledTimer(timeInterval: 0.1,
target:self,
selector:#selector(RecorderViewController.updateAudioMeter(_:)),
userInfo:nil,
repeats:true)
} else {
print("Permission to record not granted")
self.statusLabel.text = "00"
self.recordButton.isEnabled = true
self.uploadObjectSuccess = false
self.recorder.stop()
}
})
} else {
print("requestRecordPermission unrecognized")
self.statusLabel.text = "00"
self.recordButton.isEnabled = true
self.uploadObjectSuccess = false
self.recorder.stop()
}
}
func setSessionPlayback() {
let session:AVAudioSession = AVAudioSession.sharedInstance()
do {
try session.setCategory(AVAudioSessionCategoryPlayback)
} catch let error as NSError {
print("could not set session category")
print(error.localizedDescription)
}
do {
try session.setActive(true)
} catch let error as NSError {
print("could not make session active")
print(error.localizedDescription)
}
}
func setSessionPlayAndRecord() {
let session = AVAudioSession.sharedInstance()
do {
try session.setCategory(AVAudioSessionCategoryPlayAndRecord)
} catch let error as NSError {
print("could not set session category")
print(error.localizedDescription)
}
do {
try session.setActive(true)
} catch let error as NSError {
print("could not make session active")
print(error.localizedDescription)
}
}
func askForNotifications() {
NotificationCenter.default.addObserver(self,
selector:#selector(RecorderViewController.background(_:)),
name:NSNotification.Name.UIApplicationWillResignActive,
object:nil)
NotificationCenter.default.addObserver(self,
selector:#selector(RecorderViewController.foreground(_:)),
name:NSNotification.Name.UIApplicationWillEnterForeground,
object:nil)
NotificationCenter.default.addObserver(self,
selector:#selector(RecorderViewController.routeChange(_:)),
name:NSNotification.Name.AVAudioSessionRouteChange,
object:nil)
}
@objc func background(_ notification:Notification) {
print("background")
if recorder != nil {
recorder.stop()
}
}
@objc func foreground(_ notification:Notification) {
print("foreground")
}
@objc func routeChange(_ notification:Notification) {
print("routeChange \(String(describing: (notification as NSNotification).userInfo))")
if let userInfo = (notification as NSNotification).userInfo {
//print("userInfo \(userInfo)")
if let reason = userInfo[AVAudioSessionRouteChangeReasonKey] as? UInt {
//print("reason \(reason)")
switch AVAudioSessionRouteChangeReason(rawValue: reason)! {
case AVAudioSessionRouteChangeReason.newDeviceAvailable:
print("NewDeviceAvailable")
print("did you plug in headphones?")
checkHeadphones()
case AVAudioSessionRouteChangeReason.oldDeviceUnavailable:
print("OldDeviceUnavailable")
print("did you unplug headphones?")
checkHeadphones()
case AVAudioSessionRouteChangeReason.categoryChange:
print("CategoryChange")
case AVAudioSessionRouteChangeReason.override:
print("Override")
case AVAudioSessionRouteChangeReason.wakeFromSleep:
print("WakeFromSleep")
case AVAudioSessionRouteChangeReason.unknown:
print("Unknown")
case AVAudioSessionRouteChangeReason.noSuitableRouteForCategory:
print("NoSuitableRouteForCategory")
case AVAudioSessionRouteChangeReason.routeConfigurationChange:
print("RouteConfigurationChange")
}
}
}
}
func checkHeadphones() {
// check NewDeviceAvailable and OldDeviceUnavailable for them being plugged in/unplugged
let currentRoute = AVAudioSession.sharedInstance().currentRoute
if currentRoute.outputs.count > 0 {
for description in currentRoute.outputs {
if description.portType == AVAudioSessionPortHeadphones {
print("headphones are plugged in")
break
} else {
print("headphones are unplugged")
}
}
} else {
print("checking headphones requires a connection to a device")
}
}
}
// MARK: AVAudioRecorderDelegate
extension RecorderViewController : AVAudioRecorderDelegate {
func audioRecorderDidFinishRecording(_ recorder: AVAudioRecorder,
successfully flag: Bool) {
print("finished recording \(flag)")
}
func audioRecorderEncodeErrorDidOccur(_ recorder: AVAudioRecorder,
error: Error?) {
if let e = error {
print("\(e.localizedDescription)")
}
}
}