'WebRequest.Create(string)' 已过时：。请改用 HttpClient。'

Question

嗨，我正在将代码从 .net core 迁移到 .net 6.0 并高于 mesprivate static HttpWebRequest

CreateSoapRequest(string url, string action)
        {
            var httpWebRequest = (HttpWebRequest)WebRequest.Create(url);

            httpWebRequest.ContentType = "text/xml;charset=\"utf-8\"";
            httpWebRequest.Accept = "text/xml";
            httpWebRequest.Method = "POST";
            httpWebRequest.Headers.Add("SOAPAction", string.Format("\"{0}\"", action));
            return httpWebRequest;
        }

我做了下面的事情来解决这个问题

CreateSoapRequest(string url, string action)
        {
 var client = new HttpClient();
            var httpResponse = client.PostAsync(url, httpWebRequest);
            var httpWebRequest = new StringContent("", Encoding.UTF8, "text/xml");
            httpWebRequest.Headers.Add("SOAPAction", string.Format("\"{0}\"", action));
            httpWebRequest.Headers.ContentType = new MediaTypeHeaderValue("text/xml;charset=\"utf-8\"");
            return httpResponse;
}

但主要问题是在进行此更改后，我在使用此请求的方法上遇到错误

private static void AddMessageToRequest(string soapMessage, WebRequest request)
        {
            var requestStream = request.GetRequestStream();
            
            LoadXml(soapMessage).Save(requestStream);
            requestStream.Close();
        }

private static string GetResponse(WebRequest request)
        {
            try
            {
                return Read(request.GetResponse().GetResponseStream());
            }
            catch (WebException ex)
            {
                if (ex.Response != null)
                {
                    return Read(ex.Response.GetResponseStream());
                }
                throw;
            }
        }




private static string PostSoap(string url, string soapMessage, string action)
        {
            var soapRequest = CreateSoapRequest(url, action);

            AddMessageToRequest(soapMessage, soapRequest);
            return GetResponse(soapRequest);
        }

任何人都可以帮助我在这种情况下使用httpclient

Answer 1

您在使用

HttpClient

时遇到很多问题。

• 您需要使用

  HttpRequestMessage

  ，并且需要一个

  Content

  ，其中已经内部有一个流。您不会向它“索取”流媒体，而是“给予”它一个流媒体。所以你需要StreamContent。

  PostAsync

  只是上面的一个简短版本，但你不能设置标题。
• 您需要

  using

  来请求和响应。
• 缓存

  HttpClient

  以避免套接字耗尽。
• 使用

  async

await
• 。

  static HttpClient _client = new();
  
  HttpRequestMessage CreateSoapRequest(string url, string action)
  {
      var message = new HttpRequestMessage(HttpMethod.Post, url);
      message.Headers.Add("SOAPAction", "\"{action}\"");
      message.Headers.ContentType = new MediaTypeHeaderValue("text/xml;charset=\"utf-8\"");
      return httpResponse;
  }
  
  private static void AddMessageToRequest(string soapMessage, HttpRequestMessage request)
  {
      var mem = new MemoryStream();
      LoadXml(soapMessage).Save(requestStream);
      mem.Position = 0;
      message.Content = new StreamContent(mem, Encoding.UTF8, "text/xml");
  }
  
  private static async Task<string> GetResponse(HttpRequestMessage request)
  {
      using var response = await _client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
      // maybe call response.EnsureSuccessStatusCode ??
      var str = await response.ReadAsStringAsync();
      return str;
  }
  
  private static string PostSoap(string url, string soapMessage, string action)
  {
      using var soapRequest = CreateSoapRequest(url, action);
      AddMessageToRequest(soapMessage, soapRequest);
      return GetResponse(soapRequest);
  }