问IOS客户端的视频流问题(在ASP.NET WEB API2上开发的服务器)

EN

if (Request.Headers.Range != null)
    {
        try
        {
            var httpResponce = Request.CreateResponse();
            httpResponce.Content =
                new PushStreamContent((Action<Stream, HttpContent, TransportContext>) WriteContentToStream);

            return httpResponce;
        }
        catch (Exception ex)
        {
            return new HttpResponseMessage(HttpStatusCode.InternalServerError);
        }
    }
    else
    {
        return new HttpResponseMessage(HttpStatusCode.RequestedRangeNotSatisfiable);
    }

/*method for streaming*/

private async void WriteContentToStream(Stream outputStream, HttpContent content, TransportContext transportContext)
{
    string relativeFilePath = "~/App_Data/Videos/4.mp4";
    try
    {
        var filePath = System.Web.Hosting.HostingEnvironment.MapPath(relativeFilePath);

        int bufferSize = 1000;
        byte[] buffer = new byte[bufferSize];
        using (var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read))
        {
            int totalSize = (int)fileStream.Length;
            while (totalSize > 0)
            {
                int count = totalSize > bufferSize ? bufferSize : totalSize;
                int sizeOfReadedBuffer = fileStream.Read(buffer, 0, count);
                await outputStream.WriteAsync(buffer, 0, sizeOfReadedBuffer);
                totalSize -= sizeOfReadedBuffer;
            }
        }
    }
    catch (HttpException ex)
    {
        if (ex.ErrorCode == -2147023667)  
        {
            return;
        }
    }
    finally
    {
        outputStream.Close();
    }
}

public HttpResponseMessage Test()
{
    if (Request.Headers.Range != null)
    {
        try 
        {
            string relativeFilePath = "~/App_Data/Videos/4.mp4";
            var filePath = System.Web.Hosting.HostingEnvironment.MapPath(relativeFilePath);
            HttpResponseMessage partialResponse = Request.CreateResponse(HttpStatusCode.PartialContent);
            partialResponse.Headers.AcceptRanges.Add("bytes");
            var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
            partialResponse.Content = new ByteRangeStreamContent(stream, Request.Headers.Range, new MediaTypeHeaderValue("video/mp4")); 
            return partialResponse;
        }
        catch (Exception)
        {
            return new HttpResponseMessage(HttpStatusCode.InternalServerError);
        }
    }   
    else
    {
        return new HttpResponseMessage(HttpStatusCode.RequestedRangeNotSatisfiable);    
    }
}