HttpWebRequest 写入流的字节超出指定的 Content-Length 字节大小

我的解决办法：用下面红色的行，替换掉注释行，不设置ContentLength          

代码片断：  

           HttpWebRequest httpReq = (HttpWebRequest)WebRequest.Create(BaseUrl);
            httpReq.Method = "POST";     //对发送的数据不使用缓存   
            httpReq.AllowWriteStreamBuffering = false;     //设置获得响应的超时时间（300秒）   
            httpReq.Timeout = 300000;

            httpReq.ContentType = "multipart/form-data; boundary=" + strBoundary;
            long length = fs.Length + postHeaderBytes.Length + boundaryBytes.Length;
            long fileLength = fs.Length;
            httpReq.SendChunked = true;
            //httpReq.ContentLength = length;