流不可写

Question

我正在尝试从 Web SOAP Api 读取响应，并在 foreach 循环中的第二个运行上收到 Stream was not writable 错误。 list ArrayList 中的第一个值按预期工作，但第二个值表示 Stream was not writable 行上的 Stream was not writable。我做错了什么？

        WebRequest webRequest = WebRequest.Create("https://www.api.com/v2.0/xml/");
        HttpWebRequest httpRequest = (HttpWebRequest)webRequest;
        httpRequest.Method = "POST";
        httpRequest.ContentType = "text/xml; charset=utf-8";
        httpRequest.ProtocolVersion = HttpVersion.Version11;
        httpRequest.Credentials = CredentialCache.DefaultCredentials;
        Stream requestStream = httpRequest.GetRequestStream();

        StreamWriter streamWriter = new StreamWriter(requestStream, Encoding.ASCII);

        StringBuilder soapRequest;

        foreach (var bol in list) { 
        oRequest =  "<?xml version=\"1.0\" encoding=\"UTF-8\"?>";
        oRequest = oRequest + "<file>";
        oRequest = oRequest + "<IntDocNumber>" + bol + "</IntDocNumber>";
        oRequest = oRequest + "</file>";

        soapRequest  = new StringBuilder(oRequest);
         streamWriter = new StreamWriter(requestStream, Encoding.ASCII);
        streamWriter.Write(soapRequest.ToString());
        streamWriter.Close();

        //Get the Response    
        HttpWebResponse wr = (HttpWebResponse)httpRequest.GetResponse();
        StreamReader srd = new StreamReader(wr.GetResponseStream());
        string resulXmlFromWebService = srd.ReadToEnd();

        XmlDocument xml = new XmlDocument();
        xml.LoadXml(resulXmlFromWebService);

        XmlNodeList xnList = xml.SelectNodes("/root/data/item");
        }

Answer 1

所有 HTTP 通信都分为三个步骤：

客户端打开一个连接
客户端发送其 headers 和数据（在您的情况下，XML 文档）并结束输入（在您关闭请求流的情况下）
服务器发送响应并关闭连接

因此，当您关闭连接时，您将无法发送任何其他内容，因为您必须等待服务器应答。如果您想发送更多数据，请将代码的开头（您创建新 WebRequest 的位置）移到 For 循环中。

流不可写

Stream was not writable

.net

c#

streamwriter