I'd like to create a class which contains a generic dictionary which value is an generic dictionary as below:

class DList<T>
{
    public Dictionary<string, Dictionary<K, T>> Dic;
    public Init<K,T>()
    {
        Dic = new Dictionary<string, Dictionary<K, T>>();
        Dic.Add("Name", new Dictionary<string, T>());
        Dic.Add("Id", new Dictionary<int, T>());
    }
}

How can I implement this? Thanks a lot

CodePudding user response：

dynamic works. What I need is almost like a multi-keys Dictionary.

public class DList<T> : IEnumerable
{
    private List<T> list;
    private Dictionary<string, dynamic> dic;

    public T this[int i] => list[i];

    public dynamic this[string j] => dic[j];

    public int Count => list.Count;

    public DList(params string[] properties)
    {
        this.list = new List<T>();
        this.dic = new Dictionary<string, dynamic>();
        foreach (var item in properties)
        {
            this.dic.Add(item, new Dictionary<dynamic, T>());
        }
    }

    public void Add(T t)
    {
        list.Add(t);
        foreach (var item in dic)
        {
            dynamic d = t.GetType()
                .GetField(item.Key)
                .GetValue(t);
            if (item.Value.ContainsKey(d))
                continue;
            item.Value.Add(d, t);
        }
    }

    public T Get(string key, dynamic s)
    {
        return dic[key][s];
    }

    public T Get(int index)
    {
        return list[index];
    }

    public void Clear()
    {
        this.list.Clear();
        foreach(var item in dic)
        {
            item.Value.Clear();
        }
    }

    public void Sort(Comparison<T> Compare)
    {
        list.Sort(Compare);
    }

    public IEnumerator GetEnumerator()
    {
        return list.GetEnumerator();
    }
}

CodePudding user response：

class DList<K, T>
{
    public Dictionary<string, Dictionary<K, T>> Dic;
    public DList()
    {
        Dic = new Dictionary<string, Dictionary<K, T>>();
        Dic.Add("Name", new Dictionary<K, T>());
        Dic.Add("Id", new Dictionary<K, T>());
    }
}


class DList2<K, T>
{
    public Dictionary<string, Dictionary<object, T>> Dic;
    public DList2()
    {
        Dic = new Dictionary<string, Dictionary<object, T>>();
        Dic.Add("Name", new Dictionary<object, T>());
        Dic.Add("Id", new Dictionary<object, T>());
    }
}

If you know K upfront, use the DList approach. If you want to use string, int etc for K, use the approach in DList2. The inner dictionary will work just fine with keys of type int, string, etc, even if its key is declared as object.