Question

I have a class, say DerivedBindingList<T>, which is derived from BindingList<T>.

I would like to use an indexer with the derived class, and have coded it as:

        public T this[int index]
        {
            get
            {
                // Getter code
            }
            set
            {
                // Setter code
            }
        }

However, the compiler complains with the following message: “…hides inherited member ‘System.Collections.ObjectModel.Collection.this[int]’. Use the new keyword if hiding was intended.”

I can add the ‘new’ keyword and the compiler is happy, but should I be doing things differently in some way to avoid this warning?

Perhaps I have to use base.this[] somehow?

Thanks.

Answer 1

The indexer in BindingList isn’t virtual, so you can’t override it – you’ll have to just hide it if you really want to do this.

I don’t think I’d advise it though – member hiding is a recipe for confusing code. What are you trying to do? Do you definitely want to derive from BindingList<T> instead of composing it (i.e. having a member of your class of type BindingList<T>)? What is your new indexer going to do?