這是我的實現(來自open source OpenNETCF Extensions library):
public class OrderedDictionary<TKey, TValue> : IEnumerable<KeyValuePair<TKey, TValue>>
{
private Dictionary<TKey, TValue> m_dictionary;
private List<TValue> m_list = new List<TValue>();
private object m_syncRoot = new object();
public OrderedDictionary()
{
m_dictionary = new Dictionary<TKey, TValue>();
}
public OrderedDictionary(IEqualityComparer<TKey> comparer)
{
m_dictionary = new Dictionary<TKey, TValue>(comparer);
}
public void Add(TKey key, TValue value)
{
lock (m_syncRoot)
{
m_dictionary.Add(key, value);
m_list.Add(value);
}
}
public TValue this[int index]
{
get { return m_list[index]; }
}
public TValue this[TKey key]
{
get { return m_dictionary[key]; }
}
public int Count
{
get { return m_dictionary.Count; }
}
public Dictionary<TKey, TValue>.KeyCollection Keys
{
get { return m_dictionary.Keys; }
}
public Dictionary<TKey, TValue>.ValueCollection Values
{
get { return m_dictionary.Values; }
}
public void Clear()
{
lock (m_syncRoot)
{
m_dictionary.Clear();
m_list.Clear();
}
}
public bool ContainsKey(TKey key)
{
return m_dictionary.ContainsKey(key);
}
public bool ContainsValue(TValue value)
{
return m_dictionary.ContainsValue(value);
}
public void Insert(int index, TKey key, TValue value)
{
lock (m_syncRoot)
{
m_list.Insert(index, value);
m_dictionary.Add(key, value);
}
}
public void Remove(TKey key)
{
lock (m_syncRoot)
{
if (ContainsKey(key))
{
var existing = m_dictionary[key];
m_list.Remove(existing);
m_dictionary.Remove(key);
}
}
}
public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
{
return m_dictionary.GetEnumerator();
}
IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
}