Question

Using Castle Windsor, I want to configure a generic service with a type parameter; and have it implemented by a known concrete type that implements the service with a specific type as the generic parameter. Expressed as a unit test, I would like to get the following to work:

[TestClass]
public class WindsorTests
{
    [TestMethod]
    public void ResolveGenericEntity_Test()
    {
        WindsorContainer container = ConfigureContainer();
        IEntity<string> entity = container.Resolve<IEntity<string>>();
        Assert.IsNotNull(entity);
    }

    private WindsorContainer ConfigureContainer()
    {
        WindsorContainer container = new WindsorContainer();
        container.AddComponent("entity", typeof(IEntity<>), typeof(ConcreteEntity));
        return container;
    }
}

public interface IEntity<T> { }

public class ConcreteEntity : IEntity<string> {}

This test fails with the following exception:

System.InvalidOperationException:
WindsorGenericsTest.ConcreteEntity is
not a GenericTypeDefinition.
MakeGenericType may only be called on
a type for which
Type.IsGenericTypeDefinition is true.

Now, I have found a post here describing the same problem. The poster describes how this can be resolved by changing the DefaultGenericHandler.ResolveCore method. However, I don’t feel like changing the Castle code itself and running on a custom build.

Does anyone know how I can resolve this problem without modifying the Castle Windsor source code ? I am happy to implement a facility to support this, if that is what is needed.

Answer 1

Will it work if you change the line in ConfigureContainer to this?

container.AddComponent("entity", typeof(IEntity<string>), typeof(ConcreteEntity));