【发布时间】：2019-11-04 22:51:55
【问题描述】：
当我尝试在 AudioKit 播放器之间切换时，我遇到了不同类型的问题。 我会添加代码，但我会尽量简化它。
假设我有五个播放器和一个用于这些播放器的记录器，我记录播放器 1 和播放器 2 一次，如果我尝试在它们之间进行交换，则交换成功。 如果我录制 player1 两次和 player2 两次，则交换成功，但如果我录制 player1 两次和 player2 一次，则在交换期间它说 player1 不存在（nil） - 致命错误：意外发现 nil 而隐式展开一个可选值。
另一个问题：我录制了 player1 两次，player2 两次，player3 和 player4 一次，我试图在 player3 和 player4 之间交换，但它说 player3 或 player4 不存在（nil） - 致命错误：意外在隐式展开 Optional 值时发现 nil。 只有player1和player2录了一次，或者player3和player4录了两次才成功。
最后一个问题：我录了一次player1和player2一次，我想用空player3交换player1，成功了。当我尝试在 player2 和 player1（现在应该为空）之间交换时，它说 player1 不存在（nil） - 致命错误：在隐式展开可选值时意外发现 nil， 当 player1 现在应该与 player2 上的录音交换时。
帮我弄清楚为什么它如此令人沮丧。 这是代码：
@objc func startStopClipRecording1(button: UIButton, event: UIEvent) {
switch self.state {
case .readyToRecord :
if self.recorded1 == true{
while multiPlayers.contains(player1) {
if let itemToRemoveIndex = multiPlayers.firstIndex(of: player1) {
multiPlayers.remove(at: itemToRemoveIndex)
}
}
}
self.plot?.node = self.mic
self.state = .recording
_ = AVAudioTime(hostTime: UInt64(event.timestamp * secondsToTicks))
guard let lastRenderHostTime = mainMixer.avAudioNode.lastRenderTime?.hostTime else { fatalError("Engine not running!") }
let audioSession = AKSettings.session
let bufferDurationTicks = UInt64(audioSession.ioBufferDuration * secondsToTicks)
let outputLatencyTicks = UInt64(audioSession.outputLatency * secondsToTicks)
let inputLatencyTicks = UInt64(audioSession.inputLatency * secondsToTicks)
let nextRenderHostTime = lastRenderHostTime + bufferDurationTicks
let renderAfterNextHostTime = nextRenderHostTime + bufferDurationTicks
let startTimeHost = renderAfterNextHostTime + outputLatencyTicks
let playbackStartTime = AVAudioTime(hostTime: startTimeHost - outputLatencyTicks)
let recordingStartTime = AVAudioTime(hostTime: startTimeHost + inputLatencyTicks)
metronome.beatTime = 0
directRecorder?.currentTime = 0
var bars = 30 / (4 * (60 / metronome.tempo))
bars.round(.towardZero)
let durationClipRec = bars * (4 * (60 / metronome.tempo))
try? directRecorder?.recordClip(time: 0, duration: durationClipRec, tap: nil) { result in
switch result {
case .error(let error):
AKLog(error)
return
case .clip(let clip):
AKLog("direct.duration \(clip.duration)")
AKLog("direct.StartTime \(clip.startTime)")
do {
let urlInDocs = FileManager.docs.appendingPathComponent(self.filename1).appendingPathExtension(clip.url.pathExtension)
if FileManager.default.fileExists(atPath: urlInDocs.path){
FileManager.emtpyDocumentsDirectory()
}
try FileManager.default.moveItem(at: clip.url, to: urlInDocs)
self.url1 = urlInDocs
self.clip1 = clip
AKLog("Direct saved at " + urlInDocs.path)
} catch {
AKLog(error)
}
}
}
let todoDelay = 0.001
if self.recordedButNot1 == true{
multiPlayers.forEach { player in
player.play(at: playbackStartTime) }
metronome.play(at: recordingStartTime + todoDelay)
directRecorder?.start(at: recordingStartTime)
recTimer1 = Timer.scheduledTimer(timeInterval: 30.2, target:self, selector:#selector(recAction1), userInfo:nil, repeats:false)
}else{
metronome.play(at: recordingStartTime + todoDelay)
directRecorder?.start(at: recordingStartTime)
recTimer1 = Timer.scheduledTimer(timeInterval: 30.2, target:self, selector:#selector(recAction1), userInfo:nil, repeats:false)
}
case .recording :
directRecorder?.stopRecording()
directRecorder?.stop()
recordAction1()
}
}
@objc func recAction1(){
recordAction1()
}
func recordAction1(){
self.addPlayer1(withFileURL: url1)
self.instButton1.isHidden = false
swapMButton.isUserInteractionEnabled = true
self.plot?.node = nil
self.recorded1 = true
self.firstRecordDuration = true
self.recordedButNot2 = true
self.recordedButNot3 = true
self.recordedButNot4 = true
self.recordedButNot5 = true
self.metronome.stop()
self.setupUIForPlaying()
self.setupUIForRecording1()
recTimer1.invalidate()
}
private func addPlayer1(withFileURL url: URL) {
player1 = AKPlayer(url: url)
player1.buffering = .always
player1.prepare()
player1.pan = 0
self.multiPlayers.append(self.player1)
self.mainMixer.connect(input: self.player1)
}
func swap(_ str1: inout URL, _ str2: inout URL) {
(str1, str2) = (str2, str1)
}
func swapPlayers(AKplayer: AKPlayer, urlString: URL, timeLabel1: UITextField, timeLabel2: UITextField,
textField1: UITextField, textField2: UITextField, playerName1: String, playerName2: String,
instrument1: InstrumentButton, instrument2: InstrumentButton, isPlayer2Recorded: Bool, button1:
UIImageView, button2: UIImageView, maskLayer: CAShapeLayer, view: UIView){
while self.multiPlayers.contains(AKplayer) {
if let itemToRemoveIndex = self.multiPlayers.firstIndex(of: AKplayer) {
self.multiPlayers.remove(at: itemToRemoveIndex)
}
}
if playerName1 == self.recordingName1{
fileName = filename1
clip6 = clip1
}
if playerName1 == self.recordingName2{
fileName = filename2
clip6 = clip2
}
if playerName1 == self.recordingName3{
fileName = filename3
clip6 = clip3
}
if playerName1 == self.recordingName4{
fileName = filename4
clip6 = clip4
}
if playerName1 == self.recordingName5{
fileName = filename5
clip6 = clip5
}
let myLayer = plot!.waveformLayer!
myLayer.path = maskLayer.path
view.layer.addSublayer(myLayer)
self.plot?.clear()
instTextField6.text = textField1.text
recordingTimeLabel6.text = timeLabel1.text
if isPlayer2Recorded == true{
if playerName2 == self.recordingName1{
AKplayer2 = player1
}
if playerName2 == self.recordingName2{
AKplayer2 = player2
}
if playerName2 == self.recordingName3{
AKplayer2 = player3
}
if playerName2 == self.recordingName4{
AKplayer2 = player4
}
if playerName2 == self.recordingName5{
AKplayer2 = player5
}
textField1.text = textField2.text
textField2.text = instTextField6.text
selectedInstrumentToImage(button: instrument1, textField: textField1)
selectedInstrumentToImage(button: instrument2, textField: textField2)
timeLabel1.text = timeLabel2.text
timeLabel2.text = recordingTimeLabel6.text
while self.multiPlayers.contains(AKplayer2) {
if let itemToRemoveIndex = self.multiPlayers.firstIndex(of: AKplayer2) {
self.multiPlayers.remove(at: itemToRemoveIndex)
}
}
if playerName1 == self.recordingName1{
if playerName2 == self.recordingName2{
print(url1!)
print(url2!)
swap(&url1, &url2)
print(url1!)
print(url2!)
addPlayer1(withFileURL: url1)
addPlayer2(withFileURL: url2)
}
if playerName2 == self.recordingName3{
self.url1 = self.url3
self.url3 = self.url6
addPlayer1(withFileURL: url1)
addPlayer3(withFileURL: url3)
}
if playerName2 == self.recordingName4{
self.url1 = self.url4
self.url4 = self.url6
addPlayer1(withFileURL: url1)
addPlayer4(withFileURL: url4)
}
if playerName2 == self.recordingName5{
self.url1 = self.url5
self.url5 = self.url6
addPlayer1(withFileURL: url1)
addPlayer5(withFileURL: url5)
}
}
if playerName1 == self.recordingName2{
if playerName2 == self.recordingName1{
self.url2 = self.url1
self.url1 = self.url6
addPlayer2(withFileURL: url2)
addPlayer1(withFileURL: url1)
}
if playerName2 == self.recordingName3{
self.url2 = self.url3
self.url3 = self.url6
addPlayer2(withFileURL: url2)
addPlayer3(withFileURL: url3)
}
if playerName2 == self.recordingName4{
self.url2 = self.url4
self.url4 = self.url6
addPlayer2(withFileURL: url2)
addPlayer4(withFileURL: url4)
}
if playerName2 == self.recordingName5{
self.url2 = self.url5
self.url5 = self.url6
addPlayer2(withFileURL: url2)
addPlayer5(withFileURL: url5)
}
}
if playerName1 == self.recordingName3{
if playerName2 == self.recordingName1{
self.url3 = self.url1
self.url1 = self.url6
addPlayer3(withFileURL: url3)
addPlayer1(withFileURL: url1)
}
if playerName2 == self.recordingName2{
self.url3 = self.url2
self.url2 = self.url6
addPlayer3(withFileURL: url3)
addPlayer2(withFileURL: url2)
}
if playerName2 == self.recordingName4{
self.url3 = self.url4
self.url4 = self.url6
addPlayer3(withFileURL: url3)
addPlayer4(withFileURL: url4)
}
if playerName2 == self.recordingName5{
self.url3 = self.url5
self.url5 = self.url6
addPlayer3(withFileURL: url3)
addPlayer5(withFileURL: url5)
}
}
if playerName1 == self.recordingName4{
if playerName2 == self.recordingName1{
self.url4 = self.url1
self.url1 = self.url6
addPlayer4(withFileURL: url4)
addPlayer1(withFileURL: url1)
}
if playerName2 == self.recordingName2{
self.url4 = self.url2
self.url2 = self.url6
addPlayer4(withFileURL: url4)
addPlayer2(withFileURL: url2)
}
if playerName2 == self.recordingName3{
self.url4 = self.url3
self.url3 = self.url6
addPlayer4(withFileURL: url4)
addPlayer3(withFileURL: url3)
}
if playerName2 == self.recordingName5{
self.url4 = self.url5
self.url5 = self.url6
addPlayer4(withFileURL: url4)
addPlayer5(withFileURL: url5)
}
}
if playerName1 == self.recordingName5{
if playerName2 == self.recordingName1{
self.url5 = self.url1
self.url1 = self.url6
addPlayer5(withFileURL: url5)
addPlayer1(withFileURL: url1)
}
if playerName2 == self.recordingName2{
self.url5 = self.url2
self.url2 = self.url6
addPlayer5(withFileURL: url5)
addPlayer2(withFileURL: url2)
}
if playerName2 == self.recordingName3{
self.url5 = self.url3
self.url3 = self.url6
addPlayer5(withFileURL: url5)
addPlayer3(withFileURL: url3)
}
if playerName2 == self.recordingName4{
self.url5 = self.url4
self.url4 = self.url6
addPlayer5(withFileURL: url5)
addPlayer4(withFileURL: url4)
}
}
}else{
button1.isUserInteractionEnabled = false
button2.isUserInteractionEnabled = true
textField1.text = ""
textField2.text = instTextField6.text
selectedInstrumentToImage(button: instrument1, textField: textField1)
selectedInstrumentToImage(button: instrument2, textField: textField2)
timeLabel1.text = timeLabel2.text
timeLabel2.text = recordingTimeLabel6.text
if playerName1 == self.recordingName1{
recorded1 = false
reverb1.outputNode.removeTap(onBus: 0)
delay1.outputNode.removeTap(onBus: 0)
player1.outputNode.removeTap(onBus: 0)
player1 = nil
delaySlider1.isEnabled = false
reverbSlider1.isEnabled = false
volumeSlider1.isEnabled = false
soloButton1.isEnabled = false
muteButton1.isEnabled = false
if playerName2 == self.recordingName2{
self.url1 = nil
self.clip1 = nil
self.url2 = self.url6
addPlayer2(withFileURL: url2)
recorded2 = true
}
if playerName2 == self.recordingName3{
self.url1 = nil
self.clip1 = nil
self.url3 = self.url6
addPlayer3(withFileURL: url3)
recorded3 = true
}
if playerName2 == self.recordingName4{
self.url1 = nil
self.clip1 = nil
self.url4 = self.url6
addPlayer4(withFileURL: url4)
recorded4 = true
}
if playerName2 == self.recordingName5{
self.url1 = nil
self.clip1 = nil
self.url5 = self.url6
addPlayer5(withFileURL: url5)
recorded5 = true
}
}
if playerName1 == self.recordingName2{
recorded2 = false
reverb2.outputNode.removeTap(onBus: 0)
delay2.outputNode.removeTap(onBus: 0)
player2.outputNode.removeTap(onBus: 0)
player2 = nil
delaySlider2.isEnabled = false
reverbSlider2.isEnabled = false
volumeSlider2.isEnabled = false
soloButton2.isEnabled = false
muteButton2.isEnabled = false
if playerName2 == self.recordingName1{
self.url2 = nil
self.clip2 = nil
self.url1 = self.url6
addPlayer1(withFileURL: url1)
recorded1 = true
}
if playerName2 == self.recordingName3{
self.url2 = nil
self.clip2 = nil
self.url3 = self.url6
addPlayer3(withFileURL: url3)
recorded3 = true
}
if playerName2 == self.recordingName4{
self.url2 = nil
self.clip2 = nil
self.url4 = self.url6
addPlayer4(withFileURL: url4)
recorded4 = true
}
if playerName2 == self.recordingName5{
self.url2 = nil
self.clip2 = nil
self.url5 = self.url6
addPlayer5(withFileURL: url5)
recorded5 = true
}
}
if playerName1 == self.recordingName3{
recorded3 = false
reverb3.outputNode.removeTap(onBus: 0)
delay3.outputNode.removeTap(onBus: 0)
player3.outputNode.removeTap(onBus: 0)
player3 = nil
delaySlider3.isEnabled = false
reverbSlider3.isEnabled = false
volumeSlider3.isEnabled = false
soloButton3.isEnabled = false
muteButton3.isEnabled = false
if playerName2 == self.recordingName1{
self.url3 = nil
self.clip3 = nil
self.url1 = self.url6
addPlayer1(withFileURL: url1)
recorded1 = true
}
if playerName2 == self.recordingName2{
self.url3 = nil
self.clip3 = nil
self.url2 = self.url6
addPlayer2(withFileURL: url2)
recorded2 = true
}
if playerName2 == self.recordingName4{
self.url3 = nil
self.clip3 = nil
self.url4 = self.url6
addPlayer4(withFileURL: url4)
recorded4 = true
}
if playerName2 == self.recordingName5{
self.url3 = nil
self.clip3 = nil
self.url5 = self.url6
addPlayer5(withFileURL: url5)
recorded5 = true
}
}
if playerName1 == self.recordingName4{
recorded4 = false
reverb4.outputNode.removeTap(onBus: 0)
delay4.outputNode.removeTap(onBus: 0)
player4.outputNode.removeTap(onBus: 0)
player4 = nil
delaySlider4.isEnabled = false
reverbSlider4.isEnabled = false
volumeSlider4.isEnabled = false
soloButton4.isEnabled = false
muteButton4.isEnabled = false
if playerName2 == self.recordingName1{
self.url4 = nil
self.clip4 = nil
self.url1 = self.url6
addPlayer1(withFileURL: url1)
recorded1 = true
}
if playerName2 == self.recordingName2{
self.url4 = nil
self.clip4 = nil
self.url2 = self.url6
addPlayer2(withFileURL: url2)
recorded2 = true
}
if playerName2 == self.recordingName3{
self.url4 = nil
self.clip4 = nil
self.url3 = self.url6
addPlayer3(withFileURL: url3)
recorded3 = true
}
if playerName2 == self.recordingName5{
self.url4 = nil
self.clip4 = nil
self.url5 = self.url6
addPlayer5(withFileURL: url5)
recorded5 = true
}
}
if playerName1 == self.recordingName5{
recorded5 = false
reverb5.outputNode.removeTap(onBus: 0)
delay5.outputNode.removeTap(onBus: 0)
player5.outputNode.removeTap(onBus: 0)
player5 = nil
delaySlider5.isEnabled = false
reverbSlider5.isEnabled = false
volumeSlider5.isEnabled = false
soloButton5.isEnabled = false
muteButton5.isEnabled = false
if playerName2 == self.recordingName1{
self.url5 = nil
self.clip5 = nil
self.url1 = self.url6
addPlayer1(withFileURL: url1)
recorded1 = true
}
if playerName2 == self.recordingName2{
self.url5 = nil
self.clip5 = nil
self.url2 = self.url6
addPlayer2(withFileURL: url2)
recorded2 = true
}
if playerName2 == self.recordingName3{
self.url5 = nil
self.clip5 = nil
self.url3 = self.url6
addPlayer3(withFileURL: url3)
recorded3 = true
}
if playerName2 == self.recordingName4{
self.url5 = nil
self.clip5 = nil
self.url4 = self.url6
addPlayer4(withFileURL: url4)
recorded4 = true
}
}
let urlInDocs = FileManager.docs.appendingPathComponent(self.fileName!).appendingPathExtension(clip6!.url.pathExtension)
if FileManager.default.fileExists(atPath: urlInDocs.path){
FileManager.emtpyDocumentsDirectory()
}
}
}
【问题讨论】：