If second argument is not required then you can pass any value as
var menu = new Menu (dt.Rows[0][0].Tostring(),string.Empty);
Or if the value of both is to be same then pass same parameter twice as you mentioned in comment
var menu = new Menu (dt.Rows[0][0].Tostring(),dt.Rows[0][0].Tostring());
4
solved Constructor that takes 1 argument