C# 使用访问修饰符来限制对模拟的访问

Question

I want to prevent that someone interacts with a simulation in a way that he shouldn't. The only allowed way is to implement a method of the Interface "IInteraction" and add this interaction to a list. The SimulationController then goes through this list and executes the method at an appropriate time. So every class related to the simulation has to be accessible only by IInteraction (regardless from where IInteraction gets implemented).

I tried to make the simulation class internal, as this would restrict anyone from accessing it. But the Interaction needs a reference to the simulation to be able to manipulate it. A reference to it is only possible inside the assembly of the Simulation, which makes this approach useless, because that way the implementation of IInterface can't be made from a public scope.

Answer 1

IInteraction should be public. But with the Simulation being internal, an implementation of IInteraction can't access it.

The trick to this is to publish an interface ISimulation , letting IInteraction program to its interface. An internal implementation of ISimulation would remain hidden from IInteraction implementations.

public interface ISimulation {
    void SetSomethingUp();
    void DoSomething();
}
public interface IInteraction {
    void Process(ISimulator simulator);
}
...
internal class Simulator : ISimulator {
    public void SetSomethingUp() {
        ...
    }
    public void DoSomething() {
        ...
    }
}