c＃Webrequest Post和GetResponse

我正在编写一个程序，将XML提交到网站。 编写的代码工作正常， 但有时它因某些原因停止工作，抛出System.Net.ProtocolViolationException。 我可以关闭程序并重新运行 – 它再次开始工作就好了。

这是我正在使用的代码：

private string Summit(string xml) { string result = string.Empty; StringBuilder sb = new StringBuilder(); try { WebRequest request = WebRequest.Create(this.targetUrl); request.Timeout = 800 * 1000; RequestState requestState = new RequestState(xml); requestState.Request = request; request.ContentType = "text/xml"; // Set the 'Method' property to 'POST' to post data to a Uri. requestState.Request.Method = "POST"; requestState.Request.ContentType = "text/xml"; // Start the Asynchronous 'BeginGetRequestStream' method call. IAsyncResult r = (IAsyncResult)request.BeginGetRequestStream(new AsyncCallback(ReadCallBack), requestState); // Pause the current thread until the async operation completes. // Console.WriteLine("main thread waiting..."); allDone.WaitOne(); // Assign the response object of 'WebRequest' to a 'WebResponse' variable. WebResponse response = null; try { response =request.GetResponse(); } catch (System.Net.ProtocolViolationException ex) { response = null; request.Abort(); request = null; requestState = null; return ""; } //Console.WriteLine("The string has been posted."); //Console.WriteLine("Please wait for the response..."); Stream streamResponse = response.GetResponseStream(); StreamReader streamRead = new StreamReader(streamResponse); Char[] readBuff = new Char[256]; int count = streamRead.Read(readBuff, 0, 256); //StringBuilder sb = new StringBuilder(); while (count > 0) { String outputData = new String(readBuff, 0, count); sb.Append(outputData); count = streamRead.Read(readBuff, 0, 256); } // Close the Stream Object. streamResponse.Close(); streamRead.Close(); //allDone.WaitOne(); // Release the HttpWebResponse Resource. response.Close(); //return sb.ToString(); } catch (WebException webex) { Debug.WriteLine(webex.Message); } catch (System.Web.Services.Protocols.SoapException soapex) { Debug.WriteLine(soapex.Message); } catch (System.Net.ProtocolViolationException ex) { Debug.WriteLine(ex.Message); } catch (Exception ex) { Debug.WriteLine(ex.Message); } return sb.ToString(); } private static void ReadCallBack(IAsyncResult asyncResult) { try { RequestState myRequestState = (RequestState)asyncResult.AsyncState; WebRequest myWebRequest2 = myRequestState.Request; // End of the Asynchronus request. Stream responseStream = myWebRequest2.EndGetRequestStream(asyncResult); //Convert the string into a byte array. ASCIIEncoding encoder = new ASCIIEncoding(); byte[] ByteArray = encoder.GetBytes(myRequestState.Xml); // Write data to the stream. responseStream.Write(ByteArray, 0, myRequestState.Xml.Length); responseStream.Close(); } catch (WebException e) { Console.WriteLine("\nReadCallBack Exception raised!"); Console.WriteLine("\nMessage:{0}", e.Message); Console.WriteLine("\nStatus:{0}", e.Status); } allDone.Set(); } 

response =request.GetResponse()是失败并发出错误的

如果设置ContentLength> 0或SendChunked == true，则必须提供请求正文。 通过在[Begin] GetResponse之前调用[Begin] GetRequestStream来完成此操作。

任何帮助将不胜感激。

Answer 1

由于我们正在进行异步调用，因此这很棘手。

按以下顺序执行此操作：

 request.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), request) 

然后在’GetRequestStreamCallback（IAsyncResult asynchronousResult）’调用：

 request.BeginGetResponse(new AsyncCallback(GetResponseCallback), request) 

最后，在GetResponse中，请务必关闭该流：

 response.Close(); allDone.Set(); 

MSDN解释它真的很好： http ： //msdn.microsoft.com/en-us/library/system.net.httpwebrequest.begingetrequeststream.aspx