Unity Singleton Code

Question

I\'m new to Unity and am trying to write some Unity logic which initialises and register/resolves a singleton instance of the Email object so that it can be used across seve

Answer 1

If IEmail is a singleton with no dependencies (just custom arguments), you can new it up yourself:

container.RegisterInstance<IEmail>(new Email("To Name", "to@email.com"));

That will register the supplied instance as a singleton for the container.

Then you just resolve the service:

container.Resolve<OperationEntity>();

And because you are resolving a concrete type, there is no registration required. Nevertheless, if you would like that service to also be a singleton, you can register it using ContainerControlledLifetimeManager and then all calls to resolve (or when injecting it as a dependency to another class) will return the same instance:

container.RegisterType<OperationEntity>(new ContainerControlledLifetimeManager());

Answer 2

You can, for example, use this code:

public class example : MonoBehaviour
{
    public static example instance;

    public void Start()
    {
        (!instance)
            instance = this;
    }
}

Answer 3

You could use:

container.RegisterType<IEmail, Email>(new ContainerControlledLifetimeManager());

Answer 4

First, you need a proper lifetime manager the ContainerControlledLifetimeManager is for singletons.

For custom initialization, you could probably use InjectionFactory

This lets you write any code which initializes the entity.

Edit1: this should help

public static void Register(IUnityContainer container)
{
    container
        .RegisterType<IEmail, Email>(
        new ContainerControlledLifetimeManager(),
        new InjectionFactory(c => new Email(
            "To Name", 
            "to@email.com")));
}

and then

var opEntity = container.Resolve<OperationEntity>();

Edit2: To support serialization, you'd have to rebuild dependencies after you deserialize:

public class OperationEntity
{
   // make it public and mark as dependency   
   [Dependency]
   public IEmail _email { get; set;}

}

and then

OperationEntity entity = somehowdeserializeit;

// let unity rebuild your dependencies
container.BuildUp( entity );