How to inject Doctrine Entity Manager into Symfony 4 Service

Question

I have a controller

use Doctrine\ORM\EntityManagerInterface:
class ExampleController{
   public function someFunction(ExampleService $injectedService){
       $injectedService->serviceFunction();
    }
}

With a Service

use Doctrine\ORM\EntityManagerInterface;
class ExampleService{
    public function __construct(EntityManagerInterface $em){
        ...
    }    
}

However, calls to someFunction() fail due to 0 parameters being passed (the EntityManagerInterface is not being injected). I am attempting to use the EntityManager from the Service. Autowiring is on. I've tried the solutions for Symfony3 but they don't seem to work unless I'm missing something.

Edit: Here is my services.yaml:

services:
    _defaults:
        autowire: true
        autoconfigure: true
        public: false 

    App\:
        resource: '../src/*'
        exclude: '../src/{Entity,Migrations,Tests,Kernel.php}'

    App\Controller\:
        resource: '../src/Controller'
        tags: ['controller.service_arguments']

Answer 1

Use only in Symfony 4.

use Doctrine\ORM\EntityManagerInterface;
use App\Entity\Name; //if you use entity for example Name

class ExampleService{
    private $em;
    public function __construct(EntityManagerInterface $em)
    {
        $this->em = $em;
    }

    function newName($code) // for example with a entity
    {
        $name = new Name();
        $name->setCode($code); // use setter for entity

        $this->em->persist($name);
        $this->em->flush();
    }
}