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Configuring WCF Services in Code

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Windows Communication Foundation (WCF) allows developers to configure services using configuration files or code. Configuration files are useful when a service needs to be configured after being deployed. When using configuration files, an IT professional only needs to update the configuration file, no recompilation is required. Configuration files, however, can be complex and difficult to maintain. There is no support for debugging configuration files and configuration elements are referenced by names which makes authoring configuration files error-prone and difficult. WCF also allows you to configure services in code. In earlier versions of WCF (4.0 and earlier) configuring services in code was easy in self-hosted scenarios, the ServiceHost class allowed you to configure endpoints and behaviors prior to calling ServiceHost.Open. In web hosted scenarios, however, you don’t have direct access to the ServiceHost class. To configure a web hosted service you were required to create a System.ServiceModel.ServiceHostFactory that created the ServiceHostFactory and performed any needed configuration. Starting with .NET Framework 4.5, WCF provides an easier way to configure both self-hosted and web hosted services in code.

The Configure method

Simply define a public static method called Configure with the following signature in your service implementation class:

public static void Configure(ServiceConfiguration config)

The Configure method takes a ServiceConfiguration instance that enables the developer to add endpoints and behaviors. This method is called by WCF before the service host is opened. When defined, any service configuration settings specified in an app.config or web.config file will be ignored.

The following code snippet illustrates how to define the Configure method and add a service endpoint, an endpoint behavior and service behaviors:

public class Service1 : IService1
    {
        public static void Configure(ServiceConfiguration config)
        {
            ServiceEndpoint se = new ServiceEndpoint(new ContractDescription("IService1"), new BasicHttpBinding(), new EndpointAddress("basic"));
            se.Behaviors.Add(new MyEndpointBehavior());
            config.AddServiceEndpoint(se);

            config.Description.Behaviors.Add(new ServiceMetadataBehavior { HttpGetEnabled = true });
            config.Description.Behaviors.Add(new ServiceDebugBehavior { IncludeExceptionDetailInFaults = true });
        }

        public string GetData(int value)
        {
            return $"You entered: {value}";
        }

        public CompositeType GetDataUsingDataContract(CompositeType composite)
        {
            if (composite == null)
            {
                throw new ArgumentNullException("composite");
            }
            if (composite.BoolValue)
            {
                composite.StringValue += "Suffix";
            }
            return composite;
        }
    }

To enable a protocol such as https for a service, you can either explicitly add an endpoint that uses the protocol or you can automatically add endpoints by calling ServiceConfiguration.EnableProtocol(Binding) which adds an endpoint for each base address compatible with the protocol and each service contract defined. The following code illustrates how to use the ServiceConfiguration.EnableProtocol method:

public class Service1 : IService1
{
    public string GetData(int value);
    public static void Configure(ServiceConfiguration config)
    {
        // Enable "Add Service Reference" support
       config.Description.Behaviors.Add( new ServiceMetadataBehavior { HttpGetEnabled = true });
       // set up support for http, https, net.tcp, net.pipe
       config.EnableProtocol(new BasicHttpBinding());
       config.EnableProtocol(new BasicHttpsBinding());
       config.EnableProtocol(new NetTcpBinding());
       config.EnableProtocol(new NetNamedPipeBinding());
       // add an extra BasicHttpBinding endpoint at http:///basic
       config.AddServiceEndpoint(typeof(IService1), new BasicHttpBinding(),"basic");
    }
}

The settings in the <protocolMappings> section are only used if no application endpoints are added to the ServiceConfiguration programmatically.You can optionally load the service configuration from the default application configuration file by calling LoadFromConfiguration and then change the settings. The LoadFromConfiguration() class also allows you to load configuration from a centralized configuration. The following code illustrates how to implement this:

public class Service1 : IService1
{
    public void DoWork();
    public static void Configure(ServiceConfiguration config)
    {
          config.LoadFromConfiguration(ConfigurationManager.OpenMappedExeConfiguration(new ExeConfigurationFileMap { ExeConfigFilename = @"c:\sharedConfig\MyConfig.config" }, ConfigurationUserLevel.None));
    }
}

Important

Note that LoadFromConfiguration ignores <host> settings within the <service> tag of <system.serviceModel>. Conceptually, <host> is about host configuration, not service configuration, and it gets loaded before the Configure method executes.

See also