C# 可重复键值对集合

public class IComparer
    {
        /// <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
        }
    }

调用：

SortedList<int, string> list = new SortedList<int, string>(new DuplicateKeyComparer<int>());

list.Add(1,"123");
list.Add(1,"456");
list.Add(1,"789");