我使用跌破code到大文件上传到服务器，发现复制的FileStream到GetRequestStream创建字节数组，并保留在内存中。这一增长的大对象堆，我不希望它。也许有人知道如何解决这个问题？

I am using code below to upload large file to server and noticed that copying FileStream to GetRequestStream the bytes array is created and hold in memory. This increase large object heap and I don't want it. Maybe someone know how to solve this?

Stream formData = new FileStream(.....)

    HttpWebRequest request = WebRequest.Create(postUrl) as HttpWebRequest;
    using (Stream requestStream = request.GetRequestStream())
    {             
     Helpers.CopyStream(formData, requestStream);
     requestStream.Close();
    }

     public static void CopyStream(Stream fromStream, Stream toStream)
            {
                try
                {
                    int bytesRead;
                    byte[] buffer = new byte[32768];
                    while (fromStream != null && (bytesRead = fromStream.Read(buffer, 0, buffer.Length)) > 0)
                    {
                        toStream.Write(buffer, 0, bytesRead);
                    }
                }
                catch (IOException)
                {
                    //suppress empty stream response
                }
            }

内存分析器图。字节数组中GetRequestStream内部创建

Memory profiler graph. bytes array create internally in GetRequestStream

推荐答案

您可以使用 HttpWebRequest.AllowWriteStreamBuffering 禁用内部缓冲：

You can use the HttpWebRequest.AllowWriteStreamBuffering to disable internal buffering:

    HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;

    request.AllowWriteStreamBuffering = false;

    using (Stream formData = File.Open(fileName, FileMode.Open))
    using (Stream requestStream = request.GetRequestStream())
    {
        formData.CopyTo(requestStream, 32768);
    }