关于Swift：使用AVPlayer播放音频：Swift：使用AVPlayer播放音频-音频未播放，听不到音频

Swift: Playing audio using AVPlayer - Audio is not playing, cannot hear audio

我正在使用AVPlayer播放mp3音频文件。我正在使用经过测试且可以正常运行的网址。我需要使用AVPlayer，因为我需要以编程方式设置UISlider，并且AVPlayer很方便。 UISlider在音频播放时工作并更新。音频可能正在播放，但我听不到声音。我之所以这样说是因为UISlider正在工作。

更新：在模拟器上构建应用程序时，您可以听到音频。在设备上进行构建时发生问题-我的设备是XS MAX。

链接到屏幕记录ong->
访问：https：//streamable.com/nkbn8

我尝试将相同的URL用于AVAudioPlayer和音频播放，并且您可以听到。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55

private func setupAudioContent() {

let urlString ="https://s3.amazonaws.com/kargopolov/kukushka.mp3"
if let url = NSURL(string: urlString) {
audioPlayer = AVPlayer(url: url as URL)

let playerLayer = AVPlayerLayer(player: audioPlayer)
self.layer.addSublayer(playerLayer)
playerLayer.frame = self.frame

audioPlayer?.play()
audioPlayer?.volume = 1.0
audioPlayer?.addObserver(self, forKeyPath:"currentItem.loadedTimeRanges", options: .new, context: nil)

let interval = CMTime(value: 1, timescale: 2)
audioPlayer?.addPeriodicTimeObserver(forInterval: interval, queue: DispatchQueue.main, using: { (progressTime) in

let currentTime = CMTimeGetSeconds(progressTime)
let currentTimeSecondsString = String(format:"%02d", Int(currentTime.truncatingRemainder(dividingBy: 60)))
let currentTimeMinutesString = String(format:"%02d", Int(currentTime / 60))
self.currentTimeLabel.text ="\\(currentTimeMinutesString):\\(currentTimeSecondsString)"

if let duration = self.audioPlayer?.currentItem?.duration {
let durationsSeconds = CMTimeGetSeconds(duration)

self.audioSlider.value = Float(currentTime / durationsSeconds)
}
})
}
}

override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
if keyPath =="currentItem.loadedTimeRanges" {
isAudioPlaying = true

if let duration = audioPlayer?.currentItem?.duration {
let seconds = CMTimeGetSeconds(duration)
let secondsText = Int(seconds) % 60
let minutesText = String(format:"%02d", Int(seconds) / 60)
audioLengthLabel.text ="\\(minutesText):\\(secondsText)"
}
}
}

@objc func handleSliderChange() {
if let duration = audioPlayer?.currentItem?.duration {
let totalSeconds = CMTimeGetSeconds(duration)
let value = Float64(audioSlider.value) * totalSeconds
let seekTime = CMTime(value: Int64(value), timescale: 1)
audioPlayer?.seek(to: seekTime, completionHandler: { (completedSeek) in
})
}
}

预期结果：听到音频播放

实际结果：听不到音频播放。好像音频正在播放而没有声音。

使用AVPlayer时，应确保设备未处于静音模式，因为即使您的音量最大，也不会导致输出音频。

如果您想让设备保持静音模式并仍播放音频，则可以在.play()之前使用以下代码：

1
2
3
4
5
6
7

do {
try? AVAudioSession.sharedInstance().setCategory(.playback, mode: .default, options: [])
}
catch {
// report for an error
print(error)
}