Netcore webservice

using System;
using System.Text;
using System.Net;
using System.Net.Http;
using System.IO;

namespace WebSeviceTest
{
    class Program
    {
        private static string head = "<?xml version =\"1.0\" encoding=\"utf-8\"?>";
        private static string P1 = "<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><GetProductionData xmlns=\"http://tempuri.org/\">";


        private static string end = "</GetProductionData></soap:Body></soap:Envelope>";
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
            GetData("74100001", "2019-03-01", "2019-04-01");
        }

        private static string GetData(string weeks,string pstart,string pend)
        {
            string rsp = "";
            try
            {
                StringBuilder sb = new StringBuilder();
                sb.Append(head);
                sb.Append(P1);
                sb.AppendFormat("<AA>{0}</AA>", weeks);
                sb.AppendFormat("<BB>{0}</BB>", pstart);
                sb.AppendFormat("<CC>{0}</CC>", pend);
                sb.Append(end);

                Uri uri = new Uri("http://127.0.0.1/xxx.asmx");
                WebRequest webRequest = WebRequest.Create(uri);
                webRequest.ContentType = "text/xml; charset=utf-8";
                webRequest.Method = "POST";
                using (Stream requestStream = webRequest.GetRequestStream())
                {
                    byte[] paramBytes = Encoding.UTF8.GetBytes(sb.ToString());
                    requestStream.Write(paramBytes, 0, paramBytes.Length);
                }

                //响应
                WebResponse webResponse = webRequest.GetResponse();
                using (StreamReader myStreamReader = new StreamReader(webResponse.GetResponseStream(), Encoding.UTF8))
                {
                    Console.WriteLine(myStreamReader.ReadToEnd());
                    Console.WriteLine("Success...");
                }
            }
            catch(Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
            

            return rsp;

        }
    }
}