List readonly with a private set

Question

How can I expose a List so that it is readonly, but can be set privately?

This doesn\'t work:

public List myList          


        

Answer 1

If you want readonly collection use ReadOnlyCollection<T>, not List<T>:

public ReadOnlyCollection<string> MyList { get; private set; }

Answer 2

    private List<string> _items = new List<string>();         

    public ReadOnlyCollection<string> Items

    {

        get { return _items.AsReadOnly(); }

        private set { _items = value }

    }

Answer 3

In the .NET 4.5 framework you can expose only the IReadOnlyList interface. Something like:

private List<string> _mylist;
public IReadOnlyList<string> myList { get {return _myList;} }

or if you want to prevent unwanted casting to IList

private List<string> _mylist;
public IReadOnlyList<string> myList { get {return new List<string>(_myList);} }

Answer 4

I prefer to use IEnumerable

private readonly List<string> _list = new List<string>();

public IEnumerable<string> Values // Adding is not allowed - only iteration
{
   get { return _list; }
}

Answer 5

Return a ReadOnlyCollection, which implements IList<>

private List<string> myList;

public IList<string> MyList
{
  get{return myList.AsReadOnly();}
}

Answer 6

There's a collection called ReadOnlyCollection<T> - is that what you're looking for?