Question

我制作一个简单的媒体播放器。我有一个UITableViewController来自文档目录的mp3文件和UIViewController播放mp3文件。我将NSURL的{{1}}从UITableViewController传递给UIViewController，我可以播放它。我想制作按钮，这些按钮将转向下一个或上一个。我该怎么做？

代码在特定文件上传递NSURL。

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    var playerVC = (segue.destinationViewController as! UINavigationController).topViewController as! PlayMusicViewController
    var indexPath = tableView.indexPathForSelectedRow()
    var nameOfObjectForPass = listOfMP3Files![indexPath!.row] // default it's name and
    var fileManager = NSFileManager.defaultManager()

    var wayToFile = fileManager.URLsForDirectory(NSSearchPathDirectory.DocumentDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask)
    var passMusicFileURL: NSURL? // for pass mp3

    if let documentPath: NSURL = wayToFile.first as? NSURL {
        let musicFile = documentPath.URLByAppendingPathComponent(nameOfObjectForPass)
        println(musicFile)
        passMusicFileURL = musicFile
    }
    if segue.identifier == "listenMusic" {
        playerVC.nameMusicFile = nameOfObjectForPass // name
        playerVC.mp3URL = passMusicFileURL

        // test 
        playerVC.allUrlsVC = allURLS
    }

代码正在播放mp3文件

    func playMusic() {
    AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback, error: nil) // == true
    AVAudioSession.sharedInstance().setActive(true, error: nil)
    var error: NSError?
    audioPlayer = AVAudioPlayer(contentsOfURL: mp3URL, error: &error)
   // audioPlayer.prepareToPlay()
    if currentPause == nil {
    } else {
        audioPlayer.currentTime = currentPause
    }
    //
    audioPlayer.volume = 0.5
    audioPlayer.play()
}

更新

我做了以下

  var arrayMP3url: Array<AnyObject>!

    func playNextSound() {
        var queue = AVQueuePlayer(URL: mp3URL)
        var current = queue.currentItem

        var arrayForSearch = arrayMP3url as! [NSURL]

        var arrNS = arrayForSearch as NSArray

        var index = arrNS.indexOfObject(mp3URL!)
        println("index \(index)")

        println("array for search \(arrayForSearch)")

        println("current song \(current)")
    }

但我总是从NSArray

获得相同的索引

Answer 1

使用您的mp3文件数组，并使用current playing index确定indexPath，增加或减少按钮点击current playing index为Next, or, Prev，并更改mp3文件指数。重播音乐。

简单。

Ping，如果您需要更多帮助。

<强>更新

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    var playerVC = (segue.destinationViewController as! UINavigationController).topViewController as! PlayMusicViewController

    var indexPath = tableView.indexPathForSelectedRow();

    //We only need to pass current index, and array of mp3 urls

    playerVC.curIndex=indexPath.row;
    playerVC.mp3s= listOfMP3Files;

}

如上所述，只需在playerVC中声明两个属性，即

curIndex为int，mp3s为NSArray。

在功能

中

func playMusic() {

    var nameOfObjectForPass = mp3s![curIndex]; // default it's name and
    var fileManager = NSFileManager.defaultManager()

    var wayToFile = fileManager.URLsForDirectory(NSSearchPathDirectory.DocumentDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask)
    var passMusicFileURL: NSURL? // for pass mp3

    if let documentPath: NSURL = wayToFile.first as? NSURL {
        let musicFile = documentPath.URLByAppendingPathComponent(nameOfObjectForPass)
        println(musicFile)
        passMusicFileURL = musicFile
    }

    self.nameMusicFile = nameOfObjectForPass // name
    self.mp3URL = passMusicFileURL

        // test 
    self.allUrlsVC = allURLS

   AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback, error: nil) // == true
    AVAudioSession.sharedInstance().setActive(true, error: nil)
    var error: NSError?
    audioPlayer = AVAudioPlayer(contentsOfURL: mp3URL, error: &error)
   // audioPlayer.prepareToPlay()
    if currentPause == nil {
    } else {
        audioPlayer.currentTime = currentPause
    }
    //
    audioPlayer.volume = 0.5
    audioPlayer.play()
}

然后简单地定义您的下一个和上一个索引计算，如

func playNextSound(){
   self.curIndex++;
   var maxCount=self.mp3s.count-1;
   if(self.curIndex>maxCount){
         self.curIndex=maxCount;
   }

   playMusic();
}

func playPrevSound(){
   self.curIndex--;
   if(self.curIndex<0){
         self.curIndex=0;
   }

   playMusic();
}

希望它有所帮助。欢呼声。

如何在swift中播放文档目录中的下一首曲目

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