使用HttpWebRequest流式传输大型文件时出现内存exception

当使用大文件的Http.Put时，我得到Out of Memory Exception。 我正在使用代码中显示的异步模型。 我正在尝试将8K数据块发送到Windows 2008 R2服务器。 当我尝试写入超过536,868,864字节的数据块时，会始终出现exception。 下面的代码片段中的requestStream.Write方法发生exception。

寻找原因？

注意：较小的文件是PUT OK。 如果我写入本地FileStream，逻辑也可以工作。 在Win 7 Ultimate客户端计算机上运行VS 2010，.Net 4.0。

HttpWebRequest request = (HttpWebRequest)WebRequest.Create("Http://website/FileServer/filename"); request.Method = WebRequestMethods.Http.Put; request.SendChunked = true; request.AllowWriteStreamBuffering = true; ... request.BeginGetRequestStream( new AsyncCallback(EndGetStreamCallback), state); ... int chunk = 8192; // other values give same result .... private static void EndGetStreamCallback(IAsyncResult ar) { long limit = 0; long fileLength; HttpState state = (HttpState)ar.AsyncState; Stream requestStream = null; // End the asynchronous call to get the request stream. try { requestStream = state.Request.EndGetRequestStream(ar); // Copy the file contents to the request stream. FileStream stream = new FileStream(state.FileName, FileMode.Open, FileAccess.Read, FileShare.None, chunk, FileOptions.SequentialScan); BinaryReader binReader = new BinaryReader(stream); fileLength = stream.Length; // Set Position to the beginning of the stream. binReader.BaseStream.Position = 0; byte[] fileContents = new byte[chunk]; // Read File from Buffer while (limit < fileLength) { fileContents = binReader.ReadBytes(chunk); // the next 2 lines attempt to write to network and server requestStream.Write(fileContents, 0, chunk); // causes Out of memory after 536,868,864 bytes requestStream.Flush(); // I get same result with or without Flush limit += chunk; } // IMPORTANT: Close the request stream before sending the request. stream.Close(); requestStream.Close(); } } 

Answer 1

你显然有这个记录的问题 。 当AllowWriteStreamBuffering为true ，它会缓冲写入请求的所有数据 ！ 因此，“解决方案”是将该属性设置为false ：

要解决此问题，请将HttpWebRequest.AllowWriteStreamBuffering属性设置为false。