Karmic Code Monkey

People have lots of complaints around WCF. For the 3.x codebase, many don’t like the amount of configuration one has to write or code in order to get a service up and running. For example, let’s assume that we have a simple service contract, IEchoService.

[ServiceContract(Namespace="http://www.friseton.com/Echo")]
interface IEchoService
{
  [OperationContract]
  string Echo(string value);
}

The class is implemented by EchoService:

class EchoService : IEchoService
{
  public string Echo(string value)
  {
    return value;
  }
}

In .NET 3.x, we would then have to setup some endpoints, each endpoint specific to the protocol we wanted to understand. We had to remember things like “URLs that begin with net.tcp use the NetTcpBinding.” For intranet and local machine communication, this is a pain in the butt. In .NET 4.0, the common case of taking the defaults is much easier. If you plan on listening at the base URL(s) for the service, a console application can look like this:

(code only)

var netTcp = new Uri(string.Format("net.tcp://{0}/EchoService",
  Environment.MachineName));
var netPipe = new Uri(string.Format("net.pipe://{0}/EchoService",
  Environment.MachineName));
using (var host = new ServiceHost(typeof(EchoService), netTcp, netPipe))
{
  host.Open();
  Console.WriteLine("Press [Enter] to exit.");
  Console.ReadLine();
}

You could also configure the base URIs if you wanted this all to be dynamic. This mechanism only works if you don’t explicitly add any endpoints. Choosing to add any endpoint: discovery, metadata, or a specific contract WILL mean you have to specify everything. The implicit behavior will expose all contracts on the endpoint, so a service that implements 2 or more contracts will listen for all contracts when you use implicit listeners.