ios - 当我改变v​​iewController时viewWillDisappear出现错误/停止播放声音

Question

我有一些ViewCotroller，在其中点击了一个按钮-正在播放一些音频文件。我想在更改/关闭此ViewController时停止播放音频。我该怎么做？

我尝试向viewWillDisappear添加一些方法，如果我不点击任何按钮，它将崩溃。但是，如果我点击一些按钮-它将正常工作。 🙁

import UIKit
import AVFoundation

class BossViewController: UIViewController {

    var audioPlayer = AVAudioPlayer()

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

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

    //MARK: - Stop sound when we're change/close this viewController

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)

        audioPlayer.stop()
    } 

这是我的按钮的外观:

@IBAction func boss1(_ sender: AnyObject) {

        let audioFile = NSURL(fileURLWithPath: Bundle.main.path(forResource: "shamp", ofType: "mp3")!)
        do {
            audioPlayer = try AVAudioPlayer(contentsOf: audioFile as URL)
            audioPlayer.prepareToPlay()
        } catch {
            print("Problem in getting File")
        }

        audioPlayer.play()
    }

Answer 1

您可以检查音频播放器是否正在播放(如@SandeepBhandari所述)，也可以使用Bool变量来跟踪用户是否轻按了按钮:

var buttonTapped = false

@IBAction func boss1(_ sender: AnyObject) {
    ...
    buttonTapped = true
}

然后，您可以在 viewWillDisappear(_ animated: Bool)方法中检查变量:

override func viewWillDisappear(_ animated: Bool) {
    if buttonTapped {
        audioPlayer.stop()
    }
}