CODEWITHSUNDEEP
c#dependency-injectionunity-container
Tomas
Tomas

Reputation: 18097

Pass array of types to constructor using Unity Dependency Injection

I have several classes which derived from interface

public interface IMetadataItem
{
  Do();
}

public class MyClass1 : IMetadataItem
{
  public void Do()
  {
  }
}

public class MyClass2 : IMetadataItem
{
 public void Do()
 {
 }
}

I would like to bind these classes of IMetadataItem interface to constructor of another class

public class MetadataService: IMetadataService
{
  public MetadataService(IEnumerable<IMetadataItem> metadataItems)
  {
    //metadataItems always has zero(0) items
  }
}

Unfortunately I always get empty IEnumerable list.

The Unity config look like

     container.RegisterTypes(
            AllClasses.FromLoadedAssemblies().Where(type => typeof(IMetadataItem).IsAssignableFrom(type)),
            WithMappings.FromAllInterfaces,
            WithName.TypeName,
            WithLifetime.ContainerControlled);

        container.RegisterType<IMetadataService, Services.MetadataService>(new ContainerControlledLifetimeManager(),
            new InjectionConstructor(new ResolvedArrayParameter<IMetadataItem>()) );

Any idea what I am doing wrong?

Upvotes: 1

Views: 1070

Answers (1)

qujck
qujck

Reputation: 14580

For Unity v5:

You can remove the 2nd parameter InjectionConstructor from RegisterType

container.RegisterType<IMetadataService, MetadataService>(
    new ContainerControlledLifetimeManager());

For v4:

Unity does not internally understand IEnumerable<> (see here) so you will need to change the constructor to take an array instead of an enumerable

public class MetadataService: IMetadataService
{
    public MetadataService(IMetadataItem[] metadataItems)
    {
    }
}

Upvotes: 1

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