ios - 尝试使用 AVAudioPlayer 快速播放音频时出错

Question

我对编码还很陌生，我曾尝试实现此处类似问题的其他答案中建议的代码，但没有成功。该应用程序构建良好，但每次我去播放实际的音频文件时，我都会收到一条错误消息，提示“ fatal error :在展开可选值 (lldb) 时意外发现 nil”，同时突出显示 audioPlayer.play()行。

有什么想法吗？

import UIKit
import AVFoundation

class PlaySoundsViewController: UIViewController {

    var audioPlayer:AVAudioPlayer!

    override func viewDidLoad() {
        super.viewDidLoad()
        if let filePath = NSBundle.mainBundle().pathForResource("movie_quote", ofType: "mp3"),
            let filePathURL = NSURL.fileURLWithPath(filePath) {
                var audioPlayer = AVAudioPlayer(contentsOfURL: filePathURL, error: nil)

        }else{
            println("the filePath is empty OR the file did not load")
        }

        // Do any additional setup after loading the view.
    }

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


    @IBAction func playSlowAudio(sender: UIButton) {
        audioPlayer.play()
    }

Answer 1

这是播放音频和停止音频的完整工作代码:

import UIKit
import AVFoundation

class ViewController: UIViewController, AVAudioPlayerDelegate {

    @IBOutlet weak var playAudio: UIButton!
    @IBOutlet weak var stopAudio: UIButton!

    var audioPlayer : AVAudioPlayer? = AVAudioPlayer()
    override func viewDidLoad() {
        super.viewDidLoad()
        let url = NSURL.fileURLWithPath(NSBundle.mainBundle().pathForResource("we_cant_Stop", ofType: "mp3")!)
        var error : NSError?

        audioPlayer = AVAudioPlayer(contentsOfURL: url, error: &error)
        if let err = error{
            println("audioPlayer error \(err.localizedDescription)")
        }else{
            audioPlayer?.delegate = self
            audioPlayer?.prepareToPlay()
        }
    }

    @IBAction func playTapped(sender: AnyObject) {

        if let player = audioPlayer{
            player.play()
        }

    }

    @IBAction func stopTapped(sender: AnyObject) {

        if let player = audioPlayer {
            player.stop()
        }
    }
}

希望对您有所帮助。

检查 THIS示例项目以获取更多信息。