How do I specify constructor parameters in my dependency injection container in Prism?

Question

How do I inject constructor parameters in my dependencies that I configure using Prism?

I overrode RegisterTypes to register my dependencies like this:

public partial class App : PrismApplication
{
   protected override void RegisterTypes(IContainerRegistry containerRegistry)
   {
      containerRegistry.Register<IMyService, MyService>();        
   }
}

However, MyService has some constructor parameters that I need to be able to pass in. I want to be able to pass constructor parameters to MyService, similar to how I would do it like this in Unity.

containerRegistry.Register<IMyService, MyService>(
   new InjectionConstructor("param1", "param2"));

score 3 · Accepted Answer · answered May 13 '20 at 08:21

3

I'd create a handcoded IMyServiceFactory. That can pass your parameters and potential dependencies of the service.

public interface IMyServiceFactory
{
    IMyService CreateMyService();
}

internal class MyServiceFactory : IMyServiceFactory
{
    public IMyService CreateMyService() => new MyService( "param1", "param2" );
}

Have a look at this answer, too.

answered May 13 '20 at 08:21

Haukinger

10,420
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Blegh, I was hoping there was a way to do this without factories, but I guess I'm out of luck. I like your suggestion of making the factory `internal`. Thanks for the answer. – Ben Rubin May 13 '20 at 12:56
1

Regarding the `internal` you can go even more hardcore and make the product a private class within the factory (if your testing requirements permit). – Haukinger May 13 '20 at 12:58
1

Regarding the factory in itself, see it as a clear sign for everyone that says "If you use this, the product is yours. It's your responsibility to dispose it when you're done with it." I've moved to injecting `Func` instead of `Something` (with transient lifetime) because it makes clear who disposes (the consumer or the container). – Haukinger May 13 '20 at 13:01

Soleil · Answer 2 · 2020-10-17T00:46:09.160

2

Another option is to register an instance:

containerRegistry.RegisterInstance<IMyService>(new MyService("param1", "param2"));

reference: Registering Types with Prism

edited Oct 17 '20 at 00:46

answered Oct 16 '20 at 20:32

Soleil

6,404
5
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score 0 · Answer 3 · edited Apr 05 '23 at 00:51

I have tested this and it works:

containerRegistry.Register<IMyService>(() => new MyService("param1", "param2"));
containerRegistry.RegisterSingleton<IMyService>(() => new MyService("param1", "param2"));

containerRegistry.Register(typeof(IMyService), () => new MyService("param1", "param2")); 
containerRegistry.RegisteSingleton(typeof(IMyService), () => new MyService("param1", "param2"));

How do I specify constructor parameters in my dependency injection container in Prism?

3 Answers3