How to pass additional parameters when Func<t, t> is the required type?

Question

I have two relevant static methods in UserModel:

public static UserModel GetUserByUsername(String username)
{
    //do something
    return UserModel;
}

and an overload:

public static UserModel GetUserByUsername(String username, DateTime date)
{
    //do something else
    return DiffUserModel;
}

Right now, I can successfully select a

List<UserModel>

by running

... .Select(UserModel.GetUserByUsername)
  .ToList();

This is calling the overloaded method:

public static UserModel GetUserByUsername(String username)

QUESTION:

How can I call the overloaded method and pass in a DateTime parameter using similar syntax?

I'd like to be able to do something like:

... .Select(UserModel.GetUserByUsername , DateTime.Now)
      .ToList();

to get a List generated from the overloaded method.

Answer 1

Try using a lambda expression, a type of anonymous method:

.Select(x => UserModel.GetUserByUsername(x, DateTime.Now))

Answer 2

Firstly, you don't say that one method is overloaded and one is not. That method name is overloaded and both methods are overloads.

As for the question:

.Select(new Func<UserModel, string>(s => UserModel.GetUserByName(s, DateTime.Now)))

Answer 3

Just as an alternate solution, since you seem to like method groups:

.Zip(Enumerable.Repeat(DateTime.Now, whatever.Count), UserModel.GetUserByName)

Will probably do the same thing. It's a slightly awkward use of repeat, but it does end up rather simple.