C# Trick with lambdas

Question

There is some code, but the thing is very simple. I want to pass a function as a parameter, but the function is so short that it could've been created by lambda.

    class Hidden
    {
        public List<string> GetData()
        {
            return new List<string>();
        }
    }

    class Main
    {
        Dictionary<int, Hidden> dir = new Dictionary<int, Hidden>();

        public Main()
        {
            Friend f = new Friend(MethodToBeReplacedByLambda);
        }

        public List<string> MethodToBeReplacedByLambda(int id)
        {
            return dir[id].GetData();
        }
    }

    class Friend
    {
        public Friend(Func<int, List<string>> GetData)
        {
            List<string> result = GetData(4);
        }
    }

I want to delete this method

    public List<string> MethodToBeReplacedByLambda(int id)
    {
        return dir[id].GetData();
    }

And be able to pass this as a parameter by lambda. Any ideas? :D

UPDATE: I've tried:

Friend f = new Friend((int, List<string>) => dir[id].GetData());

Answer 1

Simply create a lambda that uses the int value from the function:

Friend f = new Friend(id => dir[id].GetData())

Only the parameter names (that you use) need to be passed to the lambda, and not the return value of GetData. If you have multiple parameters, wrap them in parenthesis.

Answer 2

Friend f = new Friend((id) => dir[id].GetData());