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I try stream audios with PushStreamContent and WebApi. For this I coded something. Main code;

[HttpGet]
public HttpResponseMessage StreamCall(long callId,int playSpeed)
{
    var audio = new AudioStreamHelper();

    var response = Request.CreateResponse();
    response.Content = new PushStreamContent((Action<Stream, HttpContent, TransportContext>) audio.WriteToStream, new MediaTypeHeaderValue("audio/wav"));

    return response;
}

AudioStreamHelper code;

public class AudioStreamHelper
{
    private readonly string _filename;
    protected static readonly ILogger Logger = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType.Name);
    public AudioStreamHelper()
    {
        _filename = @"C:/195545.mp3";
    }
    public async void WriteToStream(Stream outputStream, HttpContent content, TransportContext context)
    {
        try
        {
            var buffer = new byte[12365536];

            using (var audio = File.Open(_filename, FileMode.Open, FileAccess.Read,FileShare.ReadWrite))
            {
                var length = (int)audio.Length;
                var bytesRead = 1;

                while (length > 0 && bytesRead > 0)
                {
                    bytesRead = audio.Read(buffer, 0, Math.Min(length, buffer.Length));
                    await outputStream.WriteAsync(buffer, 0, bytesRead);
                    length -= bytesRead;
                }
            }
        }
        catch (HttpException ex)
        {
            Logger.Error(ex.Message);
            throw new UserFriendlyException(AppTexts.AudioStreamError);
        }
        finally
        {
            outputStream.Close();
        }
    }
}

When i debug this code; In AudioStreamHelper class WriteToStream method and await outputStream.WriteAsync(buffer, 0, bytesRead);line, my thread is locking/freezing and gives no response.I check current thread Id. It's same.(In Api and Helper class) Also, this code works another demo application with System.Net.Http.Formattion(version 4.0.0.0) My project use System.Net.Http.Formattion(version 5.1.0.0) Is associated with this condition ? I don't understand this situation.

Stormcloak
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  • Who is invoking `WriteToStream`? I only see you passing it as a delegate to `PushStreamContent`. Can you add the call-stack? – Yuval Itzchakov Apr 27 '15 at 10:17
  • 3
    Your "UserFriendlyException" can't be catched outside of WriteToStream because of "async void" signatur. "async void" is fire and forget. Use "async Task" instead. – Peter Punzenberger Apr 27 '15 at 10:21
  • @Yuval; PushStreamContent takes action type parameter and invoke WriteToStream method. In debug console, I can trace this method. But thread waiting forever in stream write line. – Stormcloak Apr 27 '15 at 10:27
  • Some Do's and Dont's for async/await: http://rarcher.azurewebsites.net/Post/PostContent/31 – Peter Punzenberger Apr 27 '15 at 10:33

0 Answers0