Prevent other classes from altering a list in a class

Question

If I have a class that contains, for example, a List and I want other classes to be able to see the list but not set it, I can declare

Answer 1

You won't be able to use an autoproperty.

public class SomeClass()
{
    private List someList;
    public IList SomeList { 
        get { return someList.AsReadOnly(); }
    }
}