swift - 线程 1 :BAD_EXC_INSTRUCTION (code=EXC_1386_INVOP, 子代码=0x0)

Question

我的代码贴在下面，不确定是什么问题，但上面列出了返回错误以及 fatal error :

unexpectedly found nil while unwrapping an Optional value

我看到了类似错误的其他答案，但所有这些都涉及诸如 if let 之类的事情，这似乎不是我的错误发生的地方，错误消息连接到靠近顶部的一行，上面写着“audioFile = try AVAudioFile(forReading: recordedAudioURL as URl)"

//
//  PlaySoundsViewController+Audio.swift
//  PitchPerfect
//
//  Copyright © 2016 Udacity. All rights reserved.
//
import UIKit
import AVFoundation

extension PlaySoundsViewController: AVAudioPlayerDelegate {
struct Alerts {
    static let DismissAlert = "Dismiss"
    static let RecordingDisabledTitle = "Recording Disabled"
    static let RecordingDisabledMessage = "You've disabled this app from recording your microphone. Check Settings."
    static let RecordingFailedTitle = "Recording Failed"
    static let RecordingFailedMessage = "Something went wrong with your recording."
    static let AudioRecorderError = "Audio Recorder Error"
    static let AudioSessionError = "Audio Session Error"
    static let AudioRecordingError = "Audio Recording Error"
    static let AudioFileError = "Audio File Error"
    static let AudioEngineError = "Audio Engine Error"
}

// raw values correspond to sender tags
enum PlayingState { case Playing, NotPlaying }


// MARK: Audio Functions

func setupAudio() {
    // initialize (recording) audio file
    do {
        audioFile = try AVAudioFile(forReading: recordedAudioURL as URL)
    } catch {
        showAlert(title: Alerts.AudioFileError, message: String(describing: error))
    }
    print("Audio has been setup")
}

func playSound(rate: Float? = nil, pitch: Float? = nil, echo: Bool = false, reverb: Bool = false) {

    // initialize audio engine components
    audioEngine = AVAudioEngine()

    // node for playing audio
    audioPlayerNode = AVAudioPlayerNode()
    audioEngine.attach(audioPlayerNode)

    // node for adjusting rate/pitch
    let changeRatePitchNode = AVAudioUnitTimePitch()
    if let pitch = pitch {
        changeRatePitchNode.pitch = pitch
    }
    if let rate = rate {
        changeRatePitchNode.rate = rate
    }
    audioEngine.attach(changeRatePitchNode)

    // node for echo
    let echoNode = AVAudioUnitDistortion()
    echoNode.loadFactoryPreset(.multiEcho1)
    audioEngine.attach(echoNode)

    // node for reverb
    let reverbNode = AVAudioUnitReverb()
    reverbNode.loadFactoryPreset(.cathedral)
    reverbNode.wetDryMix = 50
    audioEngine.attach(reverbNode)

    // connect nodes
    if echo == true && reverb == true {
        connectAudioNodes(nodes: audioPlayerNode, changeRatePitchNode, echoNode, reverbNode, audioEngine.outputNode)
    } else if echo == true {
        connectAudioNodes(nodes: audioPlayerNode, changeRatePitchNode, echoNode, audioEngine.outputNode)
    } else if reverb == true {
        connectAudioNodes(nodes: audioPlayerNode, changeRatePitchNode, reverbNode, audioEngine.outputNode)
    } else {
        connectAudioNodes(nodes: audioPlayerNode, changeRatePitchNode, audioEngine.outputNode)
    }

    // schedule to play and start the engine!
    audioPlayerNode.stop()
    audioPlayerNode.scheduleFile(audioFile, at: nil) {

        var delayInSeconds: Double = 0

        if let lastRenderTime = self.audioPlayerNode.lastRenderTime, let playerTime = self.audioPlayerNode.playerTime(forNodeTime: lastRenderTime) {

            if let rate = rate {
                delayInSeconds = Double(self.audioFile.length - playerTime.sampleTime) / Double(self.audioFile.processingFormat.sampleRate) / Double(rate)
            } else {
                delayInSeconds = Double(self.audioFile.length - playerTime.sampleTime) / Double(self.audioFile.processingFormat.sampleRate)
            }
        }

        // schedule a stop timer for when audio finishes playing
        self.stopTimer = Timer(timeInterval: delayInSeconds, target: self, selector: #selector(PlaySoundsViewController.stopAudio), userInfo: nil, repeats: false)
        RunLoop.main.add(self.stopTimer!, forMode: RunLoopMode.defaultRunLoopMode)
    }

    do {
        try audioEngine.start()
    } catch {
        showAlert(title: Alerts.AudioEngineError, message: String(describing: error))
        return
    }

    // play the recording!
    audioPlayerNode.play()
}


// MARK: Connect List of Audio Nodes

func connectAudioNodes(nodes: AVAudioNode...) {
    for x in 0..<nodes.count-1 {
        audioEngine.connect(nodes[x], to: nodes[x+1], format: audioFile.processingFormat)
    }
}

func stopAudio() {

    if let stopTimer = stopTimer {
        stopTimer.invalidate()
    }

    configureUI(playState: .NotPlaying)

    if let audioPlayerNode = audioPlayerNode {
        audioPlayerNode.stop()
    }

    if let audioEngine = audioEngine {
        audioEngine.stop()
        audioEngine.reset()
    }
}


// MARK: UI Functions

func configureUI(playState: PlayingState) {
    switch(playState) {
    case .Playing:
        setPlayButtonsEnabled(enabled: false)
        stopplaybackButton.isEnabled = true
    case .NotPlaying:
        setPlayButtonsEnabled(enabled: true)
        stopplaybackButton.isEnabled = false
    }
}

func setPlayButtonsEnabled(enabled: Bool) {
    snailButton.isEnabled = enabled
    chipmunkButton.isEnabled = enabled
    rabbitButton.isEnabled = enabled
    vaderButton.isEnabled = enabled
    echoButton.isEnabled = enabled
    reverbButton.isEnabled = enabled
}


func showAlert(title: String, message: String) {
    let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
    alert.addAction(UIAlertAction(title: Alerts.DismissAlert, style: .default, handler: nil))
    self.present(alert, animated: true, completion: nil)
}


}

Answer 1

我正在学习相同的 Udacity 类(class)，我相信这是因为 mic is not supported in the iOS 8.0+ simulator .一种可能的解决方法是将此行放入 PlaySoundsViewController 的 viewDidLoad() 函数中:

recordedAudioURL = Bundle.main.url(forResource: "yourSound", withExtension: "mp3")

...然后将名为“yourSound.mp3”的 mp3 拖到您的 PitchPerfect 项目中。这是一个 hack，但它会阻止崩溃并允许您测试该 mp3 上的音频修改按钮，但如果您想在应用程序中录制自己的样本，则需要使用实际的 iOS 设备。

编辑:我再次检查了我的整个代码库并检查了我的音频设置。在代码库中，我在 PlaySoundsViewController 中错误地放置了一个方法(为 segue 做准备)，对于音频设置，一旦我将麦克风设置为我的影院显示音频，录音就可以在模拟器中工作。祝你好运。