How to make a reference type property “readonly”

Question

I have a class Bar with a private field containing the reference type Foo. I would like to expose Foo in a public property, but I do n

Answer 1

I was thinking about similar security things. There is probably a way. Quite clear but not short. The general idea is quite simple. However I always found some ways around so never tested it. But you could check it - maybe it will work for you.

This is pseudo code, but I hope idea behind it is clear

public delegate void OnlyRuller(string s1, string s2);
public delegate void RullerCoronation(OnlyRuller d);

class Foo {
  private Foo();
  public Foo(RullerCoronation followMyOrders) {
     followMyOrders(SetMe);
  }

  private SetMe(string whatToSet, string whitWhatValue) {
     //lot of unclear but private code
  }
}

So in class which creates this property you have access to SetMe method, but it's still private so except for creator Foo looks unmutable.

Still for anything bigger than few properties this will probably became soon super mess - that's why I always preferred other ways of encapsulation. However if it's super important for you to not allow the client to change Foo, than this is one alternative.

However, as I said, this is only theory.