ios - Swift:播放录制的音频

我尝试记录，在这里可以找到一个很好的答案:
Recording audio in Swift

我可以使它工作。但是现在我想知道如何播放录制的音频。从记录中，我已经有了通用的var audioRecorder，并定义了URL路径。所以我尝试了audioRecorder.play()，但它不起作用。

我想问题出在以下事实:全局var audioRecorder是AVAudioRecorder的一个实例，要播放它，它应该是AVAudioPlayer的一个实例吗？这两者之间有何关系？

我不想复制粘贴我想了解的代码。这就是为什么我在这里简化代码。请解释为什么它在此特定代码中不起作用以及如何解决。

(我完成了很多相关的教程。问题是丢失了太多代码。我的问题是要了解这一特定部分的工作原理)

import AVFoundation
var audioRecorder:AVAudioRecorder!
@IBAction func record(sender: AnyObject) {
    var audioSession:AVAudioSession = AVAudioSession.sharedInstance()
    audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord, error: nil)
    audioSession.setActive(true, error: nil)

    var documents: AnyObject = NSSearchPathForDirectoriesInDomains( NSSearchPathDirectory.DocumentDirectory,  NSSearchPathDomainMask.UserDomainMask, true)[0]
    var str =  documents.stringByAppendingPathComponent("recordTest.caf")
    var url = NSURL.fileURLWithPath(str as String)
    println(url)

    audioRecorder = AVAudioRecorder(URL:url, settings: nil, error: nil)
    audioRecorder.record()
}

@IBAction func play(sender: AnyObject) {
   // this gives the error 'AVAudioRecorder' does not have a member named 'play'
   // audioRecorder.play()
}

最佳答案

这是录制音频，然后将其存储到文件然后播放的完整工作代码:

import UIKit
import AVFoundation

class ViewController: UIViewController, AVAudioPlayerDelegate, AVAudioRecorderDelegate {

    @IBOutlet weak var recordButton: UIButton!
    @IBOutlet weak var stopButton: UIButton!
    @IBOutlet weak var playButton: UIButton!

    var audioPlayer : AVAudioPlayer?
    var audioRecorder : AVAudioRecorder?


    override func viewDidLoad() {
        super.viewDidLoad()
        playButton.enabled = false
        stopButton.enabled = false

        // getting URL path for audio
        let dirPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
        let docDir = dirPath[0] as! String
        let soundFilePath = docDir.stringByAppendingPathComponent("sound.caf")
        let soundFileURL = NSURL(fileURLWithPath: soundFilePath)
        println(soundFilePath)

        //Setting for recorder
        let recordSettings = [AVEncoderAudioQualityKey: AVAudioQuality.Min.rawValue,
            AVEncoderBitRateKey: 16,
            AVNumberOfChannelsKey : 2,
            AVSampleRateKey: 44100.0]
        var error : NSError?
        let audioSession = AVAudioSession.sharedInstance()
        audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord, error: &error)
        if let err = error{
            println("audioSession error: \(err.localizedDescription)")
        }
        audioRecorder = AVAudioRecorder(URL: soundFileURL, settings: recordSettings as [NSObject : AnyObject], error: &error)

        if let err = error{
            println("audioSession error: \(err.localizedDescription)")
        }else{
            audioRecorder?.prepareToRecord()
        }
    }
    //record audio
    @IBAction func recordAudio(sender: AnyObject) {

        if audioRecorder?.recording == false{
            playButton.enabled = false
            stopButton.enabled = true
            audioRecorder?.record()
        }
    }
    //stop recording audio
    @IBAction func stopAudio(sender: AnyObject) {

        stopButton.enabled = false
        playButton.enabled = true
        recordButton.enabled = true

        if audioRecorder?.recording == true{
            audioRecorder?.stop()
        }else{
            audioPlayer?.stop()
        }
    }
    //play your recorded audio
    @IBAction func playAudio(sender: AnyObject) {

        if audioRecorder?.recording == false{
            stopButton.enabled = true
            recordButton.enabled = false

            var error : NSError?

            audioPlayer = AVAudioPlayer(contentsOfURL: audioRecorder?.url, error: &error)

            audioPlayer?.delegate = self

            if let err = error{
                println("audioPlayer error: \(err.localizedDescription)")
            }else{
                audioPlayer?.play()
            }
        }
    }

    func audioPlayerDidFinishPlaying(player: AVAudioPlayer!, successfully flag: Bool) {
        recordButton.enabled = true
        stopButton.enabled = false
    }

    func audioPlayerDecodeErrorDidOccur(player: AVAudioPlayer!, error: NSError!) {
        println("Audio Play Decode Error")
    }

    func audioRecorderDidFinishRecording(recorder: AVAudioRecorder!, successfully flag: Bool) {
    }

    func audioRecorderEncodeErrorDidOccur(recorder: AVAudioRecorder!, error: NSError!) {
        println("Audio Record Encode Error")
    }
}

检查THIS示例项目以获取更多信息。
在您的代码中，audioRecorder用于录制音频，audioPlayer用于播放音频。那就是为什么audioRecorder没有属性play()的原因
因此，您不能使用audioRecorder.play()。