C# cast Dictionary to Dictionary (Involving Reflection)

Question

Is it possible to cast a Dictionary to a consistent intermediate generic type? So I would be able to cast <

Answer 1

Even if you could find some way to express this, it would be the wrong thing to do - it's not true that a Dictionary is a Dictionary, so we definitely don't want to cast. Consider that if we could cast, we could try and put a string in as a value, which obviously doesn't fit!

What we can do, however, is cast to the non-generic IDictionary (which all Dictionary<,>s implement), then use that to construct a new Dictionary with the same values:

FieldInfo field = this.GetType().GetField(fieldName);
IDictionary dictionary = (IDictionary)field.GetValue(this);
Dictionary newDictionary = 
    dictionary
    .Cast()
    .ToDictionary(entry => (string)entry.Key,
                  entry => entry.Value);

(note that you can't use .Cast here for the reasons discussed here. If you're pre-C# 4, and so don't have dynamic, you'll have to do the enumeration manually, as Gibsnag's answer does)