当我播放录制的音频时，出现此错误：
致命错误：在解包可选值时意外发现 nil
在这行代码上：
SoundPlayer = try AVAudioPlayer(contentsOfURL: getFileURL())
但它在除真实设备之外的模拟器上运行良好。
ViewController.Swift：
import UIKit
import AVFoundation
class ViewController: UIViewController, AVAudioPlayerDelegate, AVAudioRecorderDelegate {
@IBOutlet var PlayBTN: UIButton!
@IBOutlet var RecordBTN: UIButton!
var soundRecorder : AVAudioRecorder!
var SoundPlayer : AVAudioPlayer!
var fileName = "audioFile.m4a"
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
setupRecorder()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func setupRecorder(){
let recordSettings = [AVSampleRateKey : NSNumber(float: Float(44100.0)),
AVFormatIDKey : NSNumber(int: Int32(kAudioFormatMPEG4AAC)),
AVNumberOfChannelsKey : NSNumber(int: 1),
AVEncoderAudioQualityKey : NSNumber(int: Int32(AVAudioQuality.Max.rawValue))]
do{
try soundRecorder = AVAudioRecorder(URL: getFileURL(), settings: recordSettings)
soundRecorder.delegate = self
soundRecorder.prepareToRecord()
}
catch let error as NSError {
error.description
}
}
func getCacheDirectory() -> String {
let paths = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)
return paths[0]
}
func getFileURL() -> NSURL{
let path = (getCacheDirectory() as NSString).stringByAppendingPathComponent(fileName)
let filePath = NSURL(fileURLWithPath: path)
return filePath
}
@IBAction func Record(sender: UIButton) {
if sender.titleLabel?.text == "Record"{
soundRecorder.record()
sender.setTitle("Stop", forState: .Normal)
PlayBTN.enabled = false
}
else{
soundRecorder.stop()
sender.setTitle("Record", forState: .Normal)
PlayBTN.enabled = false
}
}
@IBAction func PlaySound(sender: UIButton) {
if sender.titleLabel?.text == "Play" {
RecordBTN.enabled = false
sender.setTitle("Stop", forState: .Normal)
preparePlayer()
SoundPlayer.play()
}
else{
SoundPlayer.stop()
sender.setTitle("Play", forState: .Normal)
}
}
func preparePlayer(){
do{
SoundPlayer = try AVAudioPlayer(contentsOfURL: getFileURL())
SoundPlayer.delegate = self
SoundPlayer.volume = 1.0
SoundPlayer.prepareToPlay()
}
catch let error as NSError {
error.description
}
}
func audioRecorderDidFinishRecording(recorder: AVAudioRecorder, successfully flag: Bool) {
PlayBTN.enabled = true
}
func audioPlayerDidFinishPlaying(player: AVAudioPlayer, successfully flag: Bool) {
RecordBTN.enabled = true
PlayBTN.setTitle("Play", forState: .Normal)
}
@IBAction func actDone(sender: AnyObject) {
//viewRecorder.hidden = true
let fm = NSFileManager.defaultManager()
let documentsDirectory = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as String
do {
let items = try fm.contentsOfDirectoryAtPath(documentsDirectory)
for item in items {
print(item)
}
}
catch let error as NSError {
error.description
}
}
}
ViewController.Swift 的故事板文件：
附加信息：
Note:我寻找过类似的解决方案，但没有一个对我有帮助。其中一些是由于较旧的 Swift 版本和已弃用的方法造成的。一些解决方案涉及从应用程序包中播放音频文件，一些解决方案使用 Web URL。所以，这种情况是不同的（真实设备与模拟器)
这是源代码的链接谷歌云端硬盘.
在真实设备上，它需要setCategory() for AVAudioSession.sharedInstance()
并且可以下载固定的项目here too.
func setupRecorder(){
let audioSession = AVAudioSession.sharedInstance()
do {
try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord)
} catch let error as NSError {
print(error.description)
}
let recordSettings = [AVSampleRateKey : NSNumber(float: Float(44100.0)),
AVFormatIDKey : NSNumber(int: Int32(kAudioFormatMPEG4AAC)),
AVNumberOfChannelsKey : NSNumber(int: 1),
AVEncoderAudioQualityKey : NSNumber(int: Int32(AVAudioQuality.Max.rawValue))]
do{
try soundRecorder = AVAudioRecorder(URL: getFileURL(), settings: recordSettings)
soundRecorder.delegate = self
soundRecorder.prepareToRecord()
}
catch let error as NSError {
error.description
}
}
注意：音频会话是您的应用程序和 iOS 之间的中介，用于配置应用程序的音频行为。如果我们设置类别为AVAudioSessionCategoryPlayAndRecord，我们定义 iOS 音频行为以允许音频输入（录音）和输出（播放）。
参考自：音频会话编程指南