c# - 使用 httpwebrequest 调用 Web 服务方法 - 无法连接到远程服务器错误

Question

我正在调用我的 Web 服务的特定方法，但是当我创建一个新的 StreamWriter 对象时，我收到了上述错误。我不确定为什么会这样，因为我以前从未这样做过。我用来执行此操作的代码是使用此链接编写的 - Invoking an ASP.NET web service method via an http request作为引用。这是片段-

var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://localhost/Helpers/Symbology.asmx");
httpWebRequest.Headers.Add("SOAPAction", "\"http://tempuri.org/GetRelatedSymbols\"");
httpWebRequest.ContentType = "text/json";
httpWebRequest.Method = "POST";
JavaScriptSerializer serializer = new JavaScriptSerializer();

*using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))*//error occurs here
{
    string json = serializer.Serialize(relatedSymbols);
    streamWriter.Write(json);
}
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
string responseText = String.Empty;
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
     responseText = streamReader.ReadToEnd();
}

这是我的网络服务代码片段 -

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
//[System.ComponentModel.ToolboxItem(false)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
// [System.Web.Script.Services.ScriptService]
public class Symbology: System.Web.Services.WebService
{

    [WebMethod]
    public List<string> GetRelatedSymbols()
    {
        try
        {
             //code here
        }
        catch(){}
    }
}

任何人都可以帮助指出我可能做错了什么吗？

Answer 1

当我运行网络服务器时，我总是需要连接这样的 URL http://localhost:PORTNUMBER/ ...