c# general category "specialized" constructor

i have category following:

public category dropdowncontrol<t, key, value> : basecontrol
    where key: icomparable
{
    private ienumerable<t> menumerator;
    private func<t, key> mgetkey;
    private func<t, value> mgetvalue;
    private func<key, bool> miskeyincollection;

    open dropdowncontrol(string name, ienumerable<t> enumerator, func<t, key> getkey, func<t, value> getvalue, func<key, bool> iskeyincollection)
        : base(name)
    {
        menumerator = enumerator;
        mgetkey = getkey;
        mgetvalue = getvalue;

        miskeyincollection = iskeyincollection;
    }

and i wish supplement preference duty dictionaries (because support operations good own).

but problem such constructor wholly mention pivotal value nonetheless t directly, nonetheless t only keyvaluepair. there proceed tell compiler constructor t keyvaluepair, like:

public dropdowncontrol<keyvaluepair<key, value>>(string name, idictionary<key, value> dict) { ... }

currently i stationary emanate duty workaround, nonetheless i proceed constructor better.

public stationary dropdowncontrol<keyvaluepair<dkey, dvalue>, dkey, dvalue> create<dkey, dvalue>(string name, idictionary<dkey, dvalue> dictionary)
            where dkey: icomparable
        {
            relapse new dropdowncontrol<keyvaluepair<dkey, dvalue>, dkey, dvalue>(name, dictionary, kvp => kvp.key, kvp => kvp.value, pivotal => dictionary.containskey(key));
        }