How do I change my new list without changing the original list?

Question

I have a list that gets filled in with some data from an operation and I am storing it in the memory cache. Now I want another list which contains some sub data from the li

Answer 1

Even if you create a new list, the references to the items in the new list will still point to the items in the old list, so I like to use this extension method if I need a new list with new references...

public static IEnumerable Clone(this IEnumerable target) where T : ICloneable
{
    If (target.IsNull())
        throw new ArgumentException();

    List retVal = new List();

    foreach (T currentItem in target)
        retVal.Add((T)(currentItem.Clone()));

    return retVal.AsEnumerable();
}