Soundplayer在停止一次后拒绝重播

Question

我创建了一个声音播放器，可以在任何给定的时间播放一组声音中的特定声音。集合中的某个声音需要以循环方式播放。以下是我的代码：

    public class SoundService : ISoundService
{
    private Dictionary<string, SoundPlayer> SoundCollections { get; set; }
    private SoundPlayer _soundPlayerPlaceHolder;
    private readonly CancellationTokenSource _cancellationToken = new CancellationTokenSource();
    private CancellationToken _token;
    public void Play(SoundType soundType)
    {
        _token = _cancellationToken.Token;
        Task.Factory.StartNew(() => PlaySound(soundType), _token);
    }
    private void PlayLooping(SoundType soundType)
    {
        if (!SoundCollections.ContainsKey(soundType.ToString()))
        {
            s_Log.Error("Error retrieving sound from Sound collection. XXX.SoundService");
            return;
        }
        _soundPlayerPlaceHolder = SoundCollections[soundType.ToString()];
        if (_token.IsCancellationRequested)
        {
            if (_soundPlayerPlaceHolder != null)
            {
                _soundPlayerPlaceHolder.Stop();
                _soundPlayerPlaceHolder = null;
            }
            return;
        }
        _soundPlayerPlaceHolder.PlayLooping();
    }
    public void StopSound()
    {
        _cancellationToken.Cancel();
    }
    public void LoadSounds()
    {
        var sounds = Enum.GetValues(typeof (SoundType));
        SoundCollections = new Dictionary<string,SoundPlayer>();
        foreach (var soundType in sounds)
        {
            var resourceName = GetResourceNameAttribute(soundType);
            if (string.IsNullOrEmpty(resourceName))
                continue;
            try
            {
                var stream = Resources.ResourceManager.GetStream(resourceName);
                var soundPlayer = new SoundPlayer(stream);
                soundPlayer.LoadAsync();
                SoundCollections.Add(soundType.ToString(), soundPlayer);
                s_Log.Info(string.Format(@"loading sound {0}", soundType));
            }
            catch (Exception e)
            {
                s_Log.Error(e);
            }
        }
    }
    private string GetResourceNameAttribute(object enumToQuery)
    {
        var fi = enumToQuery.GetType().GetField(enumToQuery.ToString());
        var attributes = (ResourceNameAttribute[])fi.GetCustomAttributes(
            typeof(ResourceNameAttribute), false);
        return attributes.Length > 0 ? attributes[0].ResourceName : enumToQuery.ToString();
    }

    /// <summary>
    /// .
    /// </summary>
    /// <param name="aSoundType"></param>
    private void PlaySound(SoundType aSoundType)
    {
        s_Log.Info("loading sound {0}", aSoundType.ToString());
        if (aSoundType == SoundType.ItemNotFound)
        {
            PlayLooping(aSoundType);
        }
        else
        {
            if (_soundPlayerPlaceHolder == null)
            SoundCollections[aSoundType.ToString()].Play();
        }
    }
}

我遇到的问题是，在一个声音播放器在循环中播放（它正在工作），并且取消令牌被取消后，我无法再在循环中演奏相同的声音。我不知道为什么会出现这种情况，我已经尝试了许多其他线程选项（Task、BackgroundWorker），但我运气不佳。单曲播放效果很好，只是回放循环不起作用。没有例外，日志中没有任何内容。。。。我迷路了。。。想法？

Answer 1

这样的一个角落。。。。每次调用该方法时，取消令牌都是相同的。所以，当我在任务没有启动之前取消它时。。。。Derp。