Dynamically creating a new instance of IList's type

Question

My application is processing IList's. ILists of different user defined types. I'm thinking that i can use reflection to to see what type of object the IList contains and then create a new instance of that type and subsequently add that to the IList itself?

So at any one time I might be processing

IList<Customer> l;

and I'd like to create a new instance of Customer

Customer c = new Customer(0, "None")

and then add that onto the list

l.Add(c);

Obviously doing this dynamically at run-time is the crux of the problem. Hope somebody can give me some pointers. Thanks brendan

Answer 1

Try this:

    public static void AddNewElement<T>(IList<T> l, int i, string s)
    {
        T obj = (T)Activator.CreateInstance(typeof(T), new object[] { i, s });
        l.Add(obj);
    }

Usage:

    IList<Customer> l = new List<Customer>();
    l.Add(new Customer(1,"Hi there ..."));

    AddNewElement(l, 0, "None");

(EDIT):

Try this then:

    public static void AddNewElement2(IList l, int i, string s)
    {
        if (l == null || l.Count == 0)
            throw new ArgumentNullException();
        object obj = Activator.CreateInstance(l[0].GetType(), new object[] { i, s });
        l.Add(obj);
    }