WCF Service - Backward compatibility issue

Question

I'm just getting into creating some WCF services, but I have a requirement to make them backward compatible for legacy (.NET 1.1 and 2.0) client applications.

I've managed to get the services to run correctly for 3.0 and greater clients, but when I publish the services using a basicHttpBinding endpoint (which I believe is required for the compatibility I need), the service refactors my method signatures. e.g.

public bool MethodToReturnTrue(string seedValue);

appears to the client apps as

public void MethodToReturnTrue(string seedValue, out bool result, out bool MethodToReturnTrueResultSpecified);

I've tried every configuration parameter I can think of in the app.config for my self-hosting console app, but I can't seem to make this function as expected. I suppose this might lead to the fact that my expectations are flawed, but I'd be surprised that a WCF service is incapable of handling a bool return type to a down-level client.

My current app.config looks like this.

<?xml version="1.0" encoding="utf-8" ?>
<configuration>  
  <system.serviceModel>
    <services>
      <service behaviorConfiguration="MyServiceTypeBehaviors" Name="MyCompany.Services.CentreService.CentreService">
        <clear />
        <endpoint address="http://localhost:8080/CSMEX"    binding="basicHttpBinding" bindingConfiguration="" contract="IMetadataExchange" />
        <endpoint address="http://localhost:8080/CentreService" binding="basicHttpBinding" bindingName="Compatible" name="basicEndpoint" contract="MyCompany.Services.CentreService.ICentreService" />
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="MyServiceTypeBehaviors" >
            <serviceMetadata httpGetEnabled="true" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>
</configuration>

Can anyone advise, please?

Answer 1

Ah, this is killing me! I did this at work about 3 months ago, and now I can't remember all the details.

I do remember, however, that you need basicHttpBinding, and you can't use the new serializer (which is the default); you have to use the "old" XmlSerializer.

Unfortunately, I don't work at the place where I did this anymore, so I can't go look at the code. I'll call my boss and see what I can dig up.