Question

我对编码很陌生，而且我试图在其他类似问题的答案中实现建议的代码，但没有运气。该应用程序构建正常，但每次我去播放实际的音频文件时，我收到一条错误消息说＆＃34;致命错误：在解开一个可选值（lldb）＆＃34;时意外地发现了nil;而它突出显示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

以下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()
        }
    }
}

希望它会有所帮助。

检查THIS示例项目以获取更多信息。

Answer 2

以下代码应该可以正常工作：

        var soundURL: NSURL = NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("movie_quote", ofType: "mp3")!)!
        var error:NSError?
        audioPlayer = AVAudioPlayer(contentsOfURL: soundURL, error: &error)
        audioPlayer.prepareToPlay()
        audioPlayer.play()

Answer 3

您忘了在班上实施AVAudioPlayerDelegate。我认为这应该是主要问题。

此外，您还应该在{。}}中添加prepareToPlay() 功能

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

尝试使用AVAudioPlayer在swift中播放音频时出错

3 个答案: