如何使用Swift中的AVPlayer跟踪歌曲播放结束时间

Question

如何用Swift中的AVPlayer最简单的方法跟踪歌曲何时播放完毕？

AVPlayer有没有在播放结束时调用的函数，还是我应该将计时器与AVPlayer类引用组合使用？

- Mega4alik

---

不要混淆AVPlayer和AVAudioPlayer - 下面的一些答案是针对AVAudioPlayer的。 - Fattie

Answer 1

像这样的东西是可行的：

func play(url: NSURL) {
    let item = AVPlayerItem(URL: url)

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "playerDidFinishPlaying:", name: AVPlayerItemDidPlayToEndTimeNotification, object: item)

    let player = AVPlayer(playerItem: item)
    player.play()
}

func playerDidFinishPlaying(note: NSNotification) {
    // Your code here
}

不要忘记在完成时或在deinit中删除观察者！

- Jernej Strasner

---

当我测试它时，我遇到了这个错误：“终止应用程序，原因是未捕获异常'NSInvalidArgumentException'，原因是：'-[myApp.MyViewController playerDidFinishPlaying]：发送给实例的未识别选择器”。你能帮我吗？ - Ne AS

@Llg 在 "playerDidFinishPlaying:" 中忘记了冒号。 - LightMan

Answer 2

你需要创建一个实现 AVAudioPlayerDelegate 协议的对象，并将其用作 AVAudioPlayer 对象的代理。然后将它们链接在一起，例如：

audioPlayer = try! AVAudioPlayer(contentsOf: audioFileUrl)
audioPlayer.delegate = self

代理可以实现响应某些事件的方法。当音频播放完成时，此方法会触发：

func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool) {
    // ...
}

- Flimm

---

他正在使用 AVPlayer 而不是 AVAudioPlayer。 - Edward

不要忘记添加 class ViewController: AVAudioPlayerDelegate { - Hope

非常好的答案！我正在使用AVAudioPlayer，代理工作得很好。 - multitudes

我也在使用AVAudioPlayer，并且使用了代理。接下来是下一个音频问题... - Rethunk

Answer 3

适用于Swift 4.2

func play(url: URL) {
    let item = AVPlayerItem(url: url)
    NotificationCenter.default.addObserver(self, selector: #selector(self.playerDidFinishPlaying(sender:)), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: item)

    let player = AVPlayer(playerItem: item)
    player.play() 
}

@objc func playerDidFinishPlaying(sender: Notification) {
    // Your code here
}

- Return Zero

Answer 4

Swift 3 的另一个版本

NotificationCenter.default.addObserver(self, selector: #selector(self.playerDidFinishPlaying(sender:)), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: item)

func playerDidFinishPlaying(sender: Notification) {

    // Do Something
}

- Mike Carpenter

---

Mike Carpenter，我尝试了您的解决方案，但无法使其工作。请查看下一个“answer”的代码。 - Mason Ballowe

你收到了什么错误信息？我在几个项目中都使用这段代码，它可以编译并且没有任何问题地执行。 - Mike Carpenter

Answer 5

import AVFoundation

var AVPlayerCustom:AVAudioPlayer = AVAudioPlayer()


class PlayerModule: NSObject, AVAudioPlayerDelegate {

    func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool) {
        print("Finish")
    }

    func playWithData(data: Data, proc: Int) {
        //print(data)

        do {

            AVPlayerCustom = try AVAudioPlayer(data: data)

            AVPlayerCustom.delegate = self as! AVAudioPlayerDelegate

            AVPlayerCustom.prepareToPlay()
            AVPlayerCustom.play()


        }
        catch {
            print("error1")
        }
    }
}

- Lizzz

Answer 6

这里提供了一个更完整的解决方案:

import UIKit
import AVFoundation
import MediaPlayer


class ViewController: UIViewController,AVAudioPlayerDelegate {

    var player: AVAudioPlayer = AVAudioPlayer()

    @IBAction func play(_ sender: UIButton) {
        player.play()
        player.currentTime=14*60-10
        print(player.currentTime)
    }
    @IBAction func pause(_ sender: UIButton) {
        player.pause()
    }
    @IBAction func replay(_ sender: UIButton) {
        player.currentTime=0
    }


    override func viewDidLoad() {
        super.viewDidLoad()
        do{
            let audioPath = Bundle.main.path(forResource: "elon", ofType: "mp3")
            player = try AVAudioPlayer(contentsOf: URL.init(fileURLWithPath: audioPath!))
            player.prepareToPlay()
            player.delegate = self
        }
        catch{
            print(error)
        }
    }

    func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool){
        print(flag)
        print("here")
        if flag == true{

        }
    }


}

- MartianMartian

Answer 7

对于Swift3，您需要进行以下更改：

func play(url: NSURL) {
    let item = AVPlayerItem(URL: url)
    NotificationCenter.default.addObserver(self,selector:Selector("playerDidFinishPlaying"), name:  NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: item)

    let player = AVPlayer(playerItem: item)
    player.play() 
}

func playerDidFinishPlaying() {
// Your code here
} 

- Mohd Ahmed

Answer 8

SwiftUI

在SwiftUI中，我无法使用@objc函数或委托。@objc公开的函数不能在结构体中使用。一种方法是创建一个类，或者更简单的是使用AVAudioPlayer实例属性isPlaying。请参见Apple文档。

这是我用来检查音频是否已经播放完毕以相应地更新播放/暂停按钮的代码。首先，我将值保存在@State属性中：

@State private var playing: Bool = false

然后在onAppear中，我使用一个定时器来检查播放器是否仍在播放。无论如何，我都需要这个定时器来更新音频的进度。

.onAppear {
    [...]
    Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { _ in
        if !audioPlayer.isPlaying {
            playing = false
        }
    }
}

因此，当曲目播放完毕时，播放/暂停按钮会自动更新

Button(action: {
    if audioPlayer.isPlaying {
        playing = false
        self.audioPlayer.pause()
    } else if !audioPlayer.isPlaying {
        playing = true
        self.audioPlayer.play()
    }
}) {
Image(systemName: playing ? "pause.circle.fill" : "play.circle.fill")
    .resizable()
    .frame(width: 50, height: 50)
    .aspectRatio(contentMode: .fit)
}

- multitudes