How can I store same key in IDictionary?

Question

I'm using C# 4.0. I want to store (string,string) pair using IDictionary. like below:

Dictionary<string, string> _tempDicData = new Dictionary<string, string>();
      _tempDicData.Add("Hello", "xyz");
      _tempDicData.Add("Hello", "aaa");
      _tempDicData.Add("Hello", "qwert");
      _tempDicData.Add("Hello", "foo");
      _tempDicData.Add("Hello", "pqr");
      _tempDicData.Add("Hello", "abc");

but got an error:

An item with the same key has already been added.

So How can I store same key in IDictionary?

Answer 1

A class where u can add duplicated keys may look like the following:

class TDictionary<K, V>
{
    struct KeyValuePair
    {
        public K Key;
        public V Value;
    }

    private readonly List<KeyValuePair> fList = new List<KeyValuePair>();

    public void Add(K key, V value)
    {
        fList.Add(new KeyValuePair { Key = key, Value = value });
    }

    public List<V> this[K key]
    {
        get { return (from pair in fList where pair.Key.Equals(key) select pair.Value).ToList(); }
    }

    public List<K> Keys
    {
        get { return fList.Select(pair => pair.Key).ToList(); }
    }

    public List<V> Values
    {
        get { return fList.Select(pair => pair.Value).ToList(); }
    }
}