Simple SOAP Example in C#

  • I am experimenting with creating a SOAP connection to Salesforce using C#. I am using the sample code in SOAP API Developer Guide (PDF pages 22-28). It says it uses "A .NET 3.0 style reference uses services like SoapClient". I assume it was referring to the SOAPClient in Microsoft.Web.Services3. When I try to instance a SoapClient it gives the error "can't create an instance from an abstract class or interface". I added a Service Reference to the WSDL file and that worked.


    • Does anyone have any ideas on why it can't instance it? (Docs show it should work)
    • Does anyone have this example working? Can you share it?



    using System;
    using System.ServiceModel;
    using Microsoft.Web.Services3.Messaging;
    using SimpleConnect.SFProd;  // WSDL XML File
    namespace SimpleConnect
    class SimpleConnect
        private static SoapClient loginClient; // for login endpoint
        static void Main(string[] args)
            SimpleConnect sample = new SimpleConnect();
            loginClient = new SoapClient();    //************************** Error

    I don't know the answer. But I saw that the SoapClient class implemented in the Microsoft.Web.Services3.Messaging namespace is an abstract class. So it's normal that you can't instanciate it. Probably, the wsdl provided by Salesforce declare its own SoapClient class.

    Guys, I don't see how this is related to Salesforce. Did you accidentally post in the wrong forum?

    The document and example I posted is directly from the Salesforce SOAP API Developer Guide. Can you be specific on why a question regarding a Salesforce provided document and example is off-topic.

    Yes, the Salesforce documentation in Step 3: Import the WSDL File Into Your Development Platform is confusing here. They don't mean add a using to import `Microsoft.Web.Services3.Messaging`. Instead they are referencing the different output between adding a Web Reference and a Service Reference.

    If we can get this question reopened for you I'll give a more complete answer. In the short term you might find the Nothing But .Net blog series useful. In particular, have a look at the Toolkit for .NET if you want to use the REST API rather than the SOAP API.

    Still an issue. If SoapClient is supposed to be generated with the WSDL, it's not happening.

  • The key is in the previous step of the SalesForce SOAP API Quick Start.

    You can add either a .NET 2.0 style Web reference, or a .NET 3.0 style Service reference, depending on your version of Visual Studio and preferred developer environment. A .NET 3.0 style reference uses services like SoapClient instead of SforceService. (emphasis mine)

    The following section of that page details adding a web reference, but offers no guidance for adding a service reference. It's even easier than adding a web reference.

    1. Generate Your WDSL

    Browse to your instance and generate a WSDL file (same as in the Salesforce docs).

    generate Salesforce WSDL

    2. Add a Service Reference

    I'm using Visual Studio 2017. This is what the process looks like for me.

    Visual Studio add service reference dropdown

    Note that I had to set the namespace to "sForce".

    Visual Studio add service reference dialog

    3. Add a Using Statement

    The namespace of the Salesforce reference is placed inside the project reference. As you can see, there's no compile error for my reference to SoapClient, which was provided in the sForce namespace.

    using the Salesforce reference namespace

    Since the documentation gives example code for the newer service reference, it should really include instructions to set up the service reference. But hey, they're pretty good docs overall, so I guess it's fine.

    Do note that there's a performance impact to using the service instead of the web reference.

    Also note I had to use a workaround to avoid a bug in how the reference is generated from WSDL. It's described quite well in another answer.

    4. Use the Service

    Once the service is set up, you can use code from the Salesforce tutorial to log in (copied here with slight modifications):

    public class SfSession
        public static SoapClient client;
        private static SoapClient loginClient;
        private static SessionHeader sessionHeader;
        private static EndpointAddress endpoint;
        public bool Login()
            string username = "<EMAIL>";
            string password = "<PASSWORD>(<TOKEN>)";
            loginClient = new SoapClient();
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
            LoginResult lr = loginClient.login(null, username, password);
            endpoint = new EndpointAddress(lr.serverUrl);
            sessionHeader = new SessionHeader
                sessionId = lr.sessionId
            client = new SoapClient("Soap", endpoint);
            return true;
        private void Logout()

    (btw, don't leave your username/password in code... I put it there solely for testing)

    Thanks!!! I was able to get it work using the workaround and a Web Service Reference but I couldn't get it to work using Service Reference. Could you show the code for a login?

    @user2970483, just added example code.

    Thanks for this. I actually got it working yesterday with .Net as a test. I'm trying to get it working using .Net Core and it uses a Service Reference as well Microsoft WCF Web Service Reference. It is async. I just posted on it .Net Core 2.0 and async/await Usage.

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Content dated before 7/24/2021 11:53 AM

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