HttpClient & SOAP (C#)

Question

I'm trying to use the HttpClient class to send a SOAP message:

Doing so with REST seems easy (code from here) :

using System;
using System.Net.Http;
using System.Json;

namespace ConsoleApplication39
{
class Program
{
static void Main(string[] args)
{

HttpClient proxy = new HttpClient();
proxy.GetAsync("http://localhost:14892/api/Bloggers").ContinueWith((r) =>
{
HttpResponseMessage response = r.Result;
response.Content.ReadAsAsync<JsonArray>().ContinueWith(
(a)=>
{
foreach(var w in a.Result)
{
Console.WriteLine(w.ValueOrDefault("Name").ToString());
Console.WriteLine(w.ValueOrDefault("Intrest").ToString());
}
});

});

Console.ReadKey(true);

}

}
}

I would like to do something similar with SOAP.

I have the host (http://opensearch.addi.dk/2.2/) and the SOAP message to POST:

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="http://oss.dbc.dk/ns/opensearch">
  <SOAP-ENV:Body>
    <ns1:searchRequest>
      <ns1:query>dc.title=zorro AND dc.type=bog</ns1:query>
      <ns1:agency>100200</ns1:agency>
      <ns1:profile>test</ns1:profile>
      <ns1:start>1</ns1:start>
      <ns1:stepValue>10</ns1:stepValue>
    </ns1:searchRequest>
  </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

... but how to send it ?

I'll admit that this is the first SOAP Web Service I have ever used so I may have no idea what I'm doing, but in its simplest form could it be something like :

HttpClient hc = new HttpClient();
hc.BaseAddress = new Uri("http://opensearch.addi.dk/2.2/");
    
HttpContent content = *... something*
    
HttpResponseMessage rm = await hc.PostAsync("http://opensearch.addi.dk/2.2/", content);

I assume that the SOAP message should somehow be created through a HttpContent static method like HttpContent.Create(..) but I can't get that to work ...

I know this is a dumb question but I still need help :) !

tia ...

Answer 1

I needed to do this myself and since I couldn't find any answers online, here's what I worked out. This uses a simple SOAP calculator service with an 'Add' method that takes two numbers and returns the sum.

public async Task<int> AddNumbersAsync(Uri uri, int a, int b)
{
    var soapString = this.ConstructSoapRequest(a, b);
    using (var client = new HttpClient())
    {
        client.DefaultRequestHeaders.Add("SOAPAction", "http://CalculatorService/ICalculatorService/Add");
        var content = new StringContent(soapString, Encoding.UTF8, "text/xml");
        using (var response = await client.PostAsync(uri, content))
        {
            var soapResponse = await response.Content.ReadAsStringAsync();
            return this.ParseSoapResponse(soapResponse);
        }
    }
}

private string ConstructSoapRequest(int a, int b)
{
    return String.Format(@"<?xml version=""1.0"" encoding=""utf-8""?>
    <s:Envelope xmlns:s=""http://schemas.xmlsoap.org/soap/envelope/"">
        <s:Body>
            <Add xmlns=""http://CalculatorService/"">
                <a>{0}</a>
                <b>{1}</b>
            </Add>
        </s:Body>
    </s:Envelope>", a, b);
}

private int ParseSoapResponse(string response)
{
    var soap = XDocument.Parse(response);
    XNamespace ns = "http://CalculatorService/";
    var result = soap.Descendants(ns + "AddResponse").First().Element(ns + "AddResult").Value;
    return Int32.Parse(result);
}