C# Example using SOAP to retrieve a session id

result.txt

b2uv0vrjfiov41d03sk578ufq6

SOAP_CSharp_login_example.cs

using System;
using System.Text;
using System.Security.Cryptography;

namespace SugarSoap
{
    class Program
    {
        static void Main(string[] args)
        {
            string UserName = "admin";
            string Password = "password";
            string URL = "http://{site_url}/service/v4/soap.php";
            string SessionID = String.Empty;

            //SugarCRM is a web reference added that points to http://{site_url}/service/v4/soap.php?wsdl
            SugarCRM.sugarsoap SugarClient = new SugarCRM.sugarsoap();
            SugarClient.Timeout = 900000;
            SugarClient.Url = URL;

            //Create authentication object
            SugarCRM.user_auth UserAuth = new SugarCRM.user_auth();

            //Populate credentials
            UserAuth.user_name = UserName;
            UserAuth.password = getMD5(Password);

            //Try to authenticate
            SugarCRM.name_value[] LoginList = new SugarCRM.name_value[0];
            SugarCRM.entry_value LoginResult = SugarClient.login(UserAuth, "SoapTest", LoginList);
            
            //get session id
            SessionID = LoginResult.id;

            if (SessionID != String.Empty)
            {
                //print session
                Console.WriteLine(SessionID);
            }

            //Pause Window
            Console.ReadLine();
        }

        static private string getMD5(string TextString)
        {
            MD5 md5 = MD5.Create();
            byte[] inputBuffer = System.Text.Encoding.ASCII.GetBytes(TextString);
            byte[] outputBuffer = md5.ComputeHash(inputBuffer);

            StringBuilder Builder = new StringBuilder(outputBuffer.Length);
            for (int i = 0; i < outputBuffer.Length; i++)
            {
                Builder.Append(outputBuffer[i].ToString("X2"));
            }

            return Builder.ToString();
        }
    }
}