How to get around lack of covariance with IReadOnlyDictionary?

Question

I\'m trying to expose a read-only dictionary that holds objects with a read-only interface. Internally, the dictionary is write-able, and so are the objects within (see belo

Answer 1

Maybe this solutions works for you:

public class ExposesReadOnly
{
    private IDictionary InternalDict { get; set; }
    public IReadOnlyDictionary PublicList
    {
        get
        {
            IReadOnlyDictionary dictionary = new ReadOnlyDictionary(InternalDict);

            return dictionary;
        }
    }

    private class NotReadOnly : IReadOnly
    {
        public string Name { get; set; }
    }

    public void AddSomeValue()
    {
        InternalDict = new Dictionary();
        InternalDict.Add(1, new NotReadOnly() { Name = "SomeValue" });
    }
}

public interface IReadOnly
{
    string Name { get; }
}

class Program
{
    static void Main(string[] args)
    {
        ExposesReadOnly exposesReadOnly = new ExposesReadOnly();
        exposesReadOnly.AddSomeValue();

        Console.WriteLine(exposesReadOnly.PublicList[1].Name);
        Console.ReadLine();

        exposesReadOnly.PublicList[1].Name = "This is not possible!";
    }
}

Hope this helps!

Greets