Question

我尝试使用PushStreamContent和WebApi来传输音频。为此我编了一些东西。主要代码;

[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代码;

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();
        }
    }
}

当我调试这段代码时;在AudioStreamHelper类WriteToStream方法和await outputStream.WriteAsync(buffer, 0, bytesRead);行中，我的线程是锁定/冻结并且没有给出响应。我检查当前线程ID。它是一样的。（在Api和Helper类中）此外，此代码使用System.Net.Http.Formattion（版本4.0.0.0）运行另一个演示应用程序我的项目使用System.Net.Http.Formattion（版本5.1.0.0）与这种情况有关吗？我不明白这种情况。

Await Stream WriteAsync方法是锁定/冻结

0 个答案: