c# - 来自 url 的 xamarin.ios mp3 流在结束前停止

Question

我正在使用 xamarin 开发一个 ios 应用程序，其中包含一些要在应用程序中流式传输的 mp3 文件。

我用过this sample ，它似乎工作正常......

但 mp3 在结束前停止，总是在 2' 30"左右

这是我使用的代码:

public partial class PlayerViewController : UIViewController
{
    NSTimer updatingTimer;
    StreamingPlayback player;

    public event EventHandler<ErrorArg> ErrorOccurred;

    public string SourceUrl { get; private set; }

    public string Title { get; private set; }

    public PlayerOption PlayerOption { get; private set; }

    public bool IsPlaying { get; private set; }

    public PlayerViewController (PlayerOption playerOption, string sourceUrl, string title) : base ("PlayerViewController", null)
    {
        PlayerOption = playerOption;
        SourceUrl = sourceUrl;
        Title = title;
    }

    public override void ViewDidLoad ()
    {
        base.ViewDidLoad ();

        this.View = View;
        volumeSlider.TouchUpInside += SetVolume;
        playPauseButton.TouchUpInside += PlayPauseButtonClickHandler;
        headerMusic.Text = this.Title;
    }

    void SetVolume (object sender, EventArgs e)
    {
        if (player == null)
            return;

        player.Volume = volumeSlider.Value;
    }

    public override void ViewWillAppear (bool animated)
    {
        base.ViewWillAppear (animated);
        Title = PlayerOption == PlayerOption.Stream ? "Stream " : "Stream & Save";
        playPauseButton.TitleLabel.Text = "Pause";
        timeLabel.Text = string.Empty;

        // Create a shared intance session & check
        var session = AVAudioSession.SharedInstance ();
        if (session == null) {
            var alert = new UIAlertView ("Playback error", "Unable to playback stream", null, "Cancel");
            alert.Show ();
            alert.Clicked += (object sender, UIButtonEventArgs e) => alert.DismissWithClickedButtonIndex (0, true);
        } else {
            StartPlayback ();
            IsPlaying = true;

            // Set up the session for playback category
            NSError error;
            session.SetCategory (AVAudioSessionCategory.Playback, AVAudioSessionCategoryOptions.DefaultToSpeaker);
            session.OverrideOutputAudioPort (AVAudioSessionPortOverride.Speaker, out error);
        }
    }

    public override void ViewDidDisappear (bool animated)
    {
        base.ViewDidDisappear (animated);

        if (updatingTimer != null)
            updatingTimer.Invalidate ();

        if (player != null) {
            player.FlushAndClose ();
            player = null;
        }
    }

    void PlayPauseButtonClickHandler (object sender, EventArgs e)
    {
        if (player == null)
            return;

        if (IsPlaying)
            player.Pause ();
        else
            player.Play ();

        var title = IsPlaying ? "Play" : "Pause";
        playPauseButton.SetTitle (title, UIControlState.Normal);
        playPauseButton.SetTitle (title, UIControlState.Selected);
        IsPlaying = !IsPlaying;
    }

    void StartPlayback ()
    {
        try {
            var request = (HttpWebRequest)WebRequest.Create (SourceUrl);
            request.BeginGetResponse (StreamDownloadedHandler, request);
        } catch (Exception e) {
            string.Format ("Error: {0}", e.ToString ());
        }
    }

    void RaiseErrorOccurredEvent (string message)
    {
        var handler = ErrorOccurred;
        if (handler != null)
            handler (this, new ErrorArg { Description = message });
    }

    void StreamDownloadedHandler (IAsyncResult result)
    {
        var buffer = new byte [8192];
        int l = 0;
        int inputStreamLength;
        double sampleRate = 0;

        Stream inputStream;
        AudioQueueTimeline timeline = null;

        var request = result.AsyncState as HttpWebRequest;
        try {
            var response = request.EndGetResponse (result);
            var responseStream = response.GetResponseStream ();

            if (PlayerOption == PlayerOption.StreamAndSave)
                inputStream = GetQueueStream (responseStream);
            else
                inputStream = responseStream;

            using (player = new StreamingPlayback ()) {
                player.OutputReady += delegate {
                    timeline = player.OutputQueue.CreateTimeline ();
                    sampleRate = player.OutputQueue.SampleRate;
                };

                InvokeOnMainThread (delegate {
                    if (updatingTimer != null)
                        updatingTimer.Invalidate ();

                    updatingTimer = NSTimer.CreateRepeatingScheduledTimer (0.5, (timer) => RepeatingAction (timeline, sampleRate));
                });

                while ((inputStreamLength = inputStream.Read (buffer, 0, buffer.Length)) != 0 && player != null) {
                    l += inputStreamLength;
                    player.ParseBytes (buffer, inputStreamLength, false, l == (int)response.ContentLength);

                    InvokeOnMainThread (delegate {
                        progressBar.Progress = l / (float)response.ContentLength;
                    });
                }
            }

        } catch (Exception e) {
            RaiseErrorOccurredEvent ("Error fetching response stream\n" + e);
            Debug.WriteLine (e);
            InvokeOnMainThread (delegate {
                if (NavigationController != null)
                    NavigationController.PopToRootViewController (true);
            });
        }
    }

    void RepeatingAction (AudioQueueTimeline timeline, double sampleRate)
    {
        var queue = player.OutputQueue;
        if (queue == null || timeline == null)
            return;

        bool disc = false;
        var time = new AudioTimeStamp ();
        queue.GetCurrentTime (timeline, ref time, ref disc);

        playbackTime.Text = FormatTime (time.SampleTime / sampleRate);
    }

    string FormatTime (double time)
    {
        double minutes = time / 60;
        double seconds = time % 60;

        return String.Format ("{0}:{1:D2}", (int)minutes, (int)seconds);
    }

    Stream GetQueueStream (Stream responseStream)
    {
        var queueStream = new QueueStream (Environment.GetFolderPath (Environment.SpecialFolder.Personal) + "/copy.mp3");
        var t = new Thread ((x) => {
            var tbuf = new byte [8192];
            int count;

            while ((count = responseStream.Read (tbuf, 0, tbuf.Length)) != 0)
                queueStream.Push (tbuf, 0, count);

        });
        t.Start ();
        return queueStream;
    }
}

我该如何解决这个问题？ 提前致谢

Answer 1

遇到了同样的问题。 打开 StreamingPlayback.cs 文件

改变变量

int bufferSize = 128 * 1024

进入

int bufferSize = 128 * 128

或尝试其他尺寸..

对我有用