Use your own IComparer!
Like already stated in some other answers, you should use your own comparer class. For this sake I use a generic IComparer class, that works with anything that implements IComparable:
/// <summary>
/// Comparer for comparing two keys, handling equality as beeing greater
/// Use this Comparer e.g. with SortedLists or SortedDictionaries, that don't allow duplicate keys
/// </summary>
/// <typeparam name="TKey"></typeparam>
public class DuplicateKeyComparer<TKey>
:
IComparer<TKey> where TKey : IComparable
{
#region IComparer<TKey> Members
public int Compare(TKey x, TKey y)
{
int result = x.CompareTo(y);
if (result == 0)
return 1; // Handle equality as being greater. Note: this will break Remove(key) or
else // IndexOfKey(key) since the comparer never returns 0 to signal key equality
return result;
}
#endregion
}
You will use it when instancing a new SortedList, SortedDictionary etc:
SortedList<int, MyValueClass> slist = new SortedList<int, MyValueClass>(new DuplicateKeyComparer<int>());
Here int is the key that can be duplicate.