ios - 自定义 TableViewController 在 Swift 3 中播放声音和崩溃

Question

我正在 Swift 3 中使用音频数组。

import Foundation
import UIKit
import AVFoundation


class TableViewController: UITableViewController, AVAudioPlayerDelegate {

    var players: [AVAudioPlayer] = []
    var audioFileNames = [String?]()

    override func viewDidLoad() {        
        audioFileNames = [ "ɔɪ", "eə", "aʊ", "eɪ"]
    }

我让各个声音出现在自定义单元格中。如果我按下一个单元格，声音就会播放，但是当我按下另一个单元格时，应用程序就会卡住并崩溃。

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.audioFileNames.count
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell:UITableViewCell = tableView.dequeueReusableCell(withIdentifier: "Cell")! as UITableViewCell
        cell.textLabel?.text = self.audioFileNames[indexPath.row]

        return cell
    }

代码在此函数处中断。

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        players = [setupAudioPlayerWithFile(file: self.audioFileNames[indexPath.row]! as String,  type: "mp3")!]
        players[indexPath.row].play()
    }

    func setupAudioPlayerWithFile(file: String, type: String) -> AVAudioPlayer?  {
        let path = Bundle.main.path(forResource: file as String, ofType: type as String)
        let url = NSURL.fileURL(withPath: path!)

        var audioPlayer:AVAudioPlayer?

        do {
            try audioPlayer = AVAudioPlayer(contentsOf: url)
        } catch {
            print("Player not available")
        }

        return audioPlayer
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    } 
}

Answer 1

1. 您必须在 viewDidLoad 中初始化players

   players = Array(repeating: nil, count: audioFileNames.count)
   

2. 使用前必须检查已启动的播放器

   if players[indexPath.row] == nil {
       players[indexPath.row] = setupAudioPlayerWithFile(file: self.audioFileNames[indexPath.row]! as String,  type: "mp3")    
   }