WebSerrvic代码：

        [WebMethod]public string Test(string p1, string p2){return p1 + "_" + p2;}

以下是 SOAP 1.2 请求和响应示例。所显示的占位符需替换为实际值。

POST /Service1.asmx HTTP/1.1
Host: localhost
Content-Type: text/xml; charset=utf-8
Content-Length: length
SOAPAction: "http://tempuri.org/Test"<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"><soap:Body><Test xmlns="http://tempuri.org/"><p1>string</p1><p2>string</p2></Test></soap:Body>
</soap:Envelope>

方式1：使用FormUrlEncodedContent传参数调用，内部是拼接成一个?+&的格式

   public async Task<string> Call(){Dictionary<string, string> parameters =new Dictionary<string, string>();
parameters.Add("p1","1");
parameters.Add("p2","2");string xmlResult = string.Empty;HttpContent httpContent = new FormUrlEncodedContent(parameters); HttpClient httpClient = new HttpClient();HttpResponseMessage response = httpClient.PostAsync("http://localhost/Service1.asmx", httpContent).Result;var statusCode = response.StatusCode;if (statusCode == HttpStatusCode.OK){xmlResult = await response.Content.ReadAsStringAsync();}return xmlResult;}

方式二：使用xml的格式调用

        public async Task<string> CallByXML(){Dictionary<string, string> parameters =new Dictionary<string, string>();
parameters.Add("p1","1");
parameters.Add("p2","2");string xmlResult = string.Empty;string xml = $@" 
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"><soap:Body><Test xmlns="http://tempuri.org/"><p1>{parameters["p1"]}</p1><p2>{parameters["p2"]}</p2></Test></soap:Body>
</soap:Envelope>
";HttpContent httpContent = new StringContent(xml, Encoding.UTF8, "text/xml");httpContent.Headers.Add("SOAPAction", "http://tempuri.org/Test"); HttpClient httpClient = new HttpClient();HttpResponseMessage response = httpClient.PostAsync("http://localhost/Service1.asmx", httpContent).Result;var statusCode = response.StatusCode;if (statusCode == HttpStatusCode.OK){xmlResult = await response.Content.ReadAsStringAsync();}return xmlResult;}

方式三：通过服务引用的方式调用

ServiceReference1.Service1Soap service1Soap = new ServiceReference1.Service1SoapClient
(ServiceReference1.Service1SoapClient.EndpointConfiguration.Service1Soap
);
var res = service1Soap.Test("1", "2").Result;

响应后的XML处理

        public string GetResultByXML(string xmlResult){string xmlText=string.Empty;var xmlobj = new System.Xml.XmlDocument();xmlobj.LoadXml(xmlResult);if (!string.IsNullOrEmpty(xmlobj.InnerText)){xmlText=xmlobj.InnerText;}return xmlText;}