如何持续检查 AVAudioplayer 是否已在 Swift 中播放完毕？答案

【问题标题】：How do I continuously check if AVAudioplayer is done playing in Swift?如何持续检查 AVAudioplayer 是否已在 Swift 中播放完毕？
【发布时间】：2015-09-28 22:15:30
【问题描述】：

我制作了一个播放音频的简单应用。现在我想在音频播放完毕后自动将“暂停”按钮更改为“播放”。我该如何检查？代码如下：

import UIKit
import AVFoundation

class ViewController: UIViewController {
@IBOutlet weak var PausePlay: UIButton!
var BackgroundAudio = AVAudioPlayer(contentsOfURL: NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("M.I.A.-DoubleBubbleTrouble", ofType: "mp3")!), error: nil)

override func viewDidLoad() {
    super.viewDidLoad()        
    BackgroundAudio.play()

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

@IBAction func Stop(sender: AnyObject) {
    if(BackgroundAudio.playing) {
    BackgroundAudio.stop()
    BackgroundAudio.currentTime = 0
    PausePlay.setTitle("Play", forState: .Normal)
    } else {
        BackgroundAudio.currentTime = 0
    }
}

@IBAction func Restart(sender: AnyObject) {
    if(BackgroundAudio.playing==false){
        PausePlay.setTitle("Pause", forState: .Normal)
    }
    BackgroundAudio.stop()
    BackgroundAudio.currentTime = 0
    BackgroundAudio.play()
}

@IBAction func PausePlay(sender: AnyObject) {
    if(BackgroundAudio.playing){
        BackgroundAudio.stop()
        PausePlay.setTitle("Play", forState: UIControlState.Normal)
    } else {
        BackgroundAudio.play()
        PausePlay.setTitle("Pause", forState: .Normal)
    }
}

if (BackgroundAudio.playing == false) {
PausePlay.setTitle("Play", forState: .Normal)
}   
}

最后一个 if 语句应该在函数内部，但是我如何（连续）调用该函数？

【问题讨论】：

标签： ios swift audio

【解决方案1】：

您不必不断检查 - 您应该在视图控制器中实现 AVAudioPlayerDelegate 协议：https://developer.apple.com/library/ios/documentation/AVFoundation/Reference/AVAudioPlayerDelegateProtocolReference/index.html#//apple_ref/occ/intfm/AVAudioPlayerDelegate/audioPlayerDidFinishPlaying:successfully:

请参阅：audioPlayerDidFinishPlaying:successfully:。我想你会发现它与你想做的完全相反，这实际上是正确的方法。这样，您的播放器将简单地调用您定义的“结束”函数。

【讨论】：

【解决方案2】：

这么多重复的问题...这是我重复的答案：

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{

        }
    }


}

【讨论】：