通过文件流输出的下载功能遇到的诡异问题

通过文件流输出下载附件，内网下载没有问题，但外网访问下载时，前几次没有问题，多点几次就出现：502 Bad Gateway The server returned an invalid or incomplete response之前我以为是下载大文件时，输出来不及响应造成的，但我改了代码，大文件分段输出了，每段只有10字节，但还是有问题。好奇怪啊！ iStream = new MemoryStream(d.Content);                    long dataToRead = iStream.Length;                    // Read the bytes.
                    while (dataToRead > 0)
                    {
                        // Verify that the client is connected.
                        if (Response.IsClientConnected)
                        {
                            // Read the data in buffer.
                            int length = iStream.Read(buffer, 0, 100);                            // Write the data to the current output stream.
                            Response.OutputStream.Write(buffer, 0, length);                            // Flush the data to the HTML output.
                            Response.Flush();                            buffer = new Byte[100];
                            dataToRead = dataToRead - length;
                        }
                        else
                        {
                            //prevent infinite loop if user disconnects
                            dataToRead = -1;
                        }
                    }
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