CSharp mimicking JavaScript design pattern

Simplest C# code so far I can think of equivalent to the JavaScript design pattern to allow private members.

The original JavaScript code can be found here:

http://www.crockford.com/javascript/private.html

For the ease of comparison, the JavaScript code from the above link is also pasted here,

function Container(param) {

    function dec() {
        if (secret > 0) {
            secret -= 1;
            return true;
        } else {
            return false;
        }
    }

    this.member = param;
    var secret = 3;
    var that = this;

    this.service = function () {
        return dec() ? that.member : null;
    };
}

Following is the equivalent C# code,

class Program
{
    class Container
    {
        // delegates
        delegate bool JsPrivateDelegate();
        public delegate dynamic ServiceDelegate();

        // constructor
        public Container(dynamic param)
        {
            var secret = 3;
            JsPrivateDelegate dec = delegate()
                {
                    if (secret <= 0) return false;
                    secret--;
                    return true;
                };
            Member = param;
            Service = () => dec() ? Member : null;
        }

        public dynamic Member { get; private set; } // public property
        public ServiceDelegate Service { get; private set; }    // public 'method'
    }
    
    static void Main(string[] args)
    {
        var c = new Container("haha");
        dynamic s;
        do
        {
            s = c.Service();    // consumes the service
            Console.WriteLine("{0}", s ?? "<null>");
        } while (s != null);
    }
}

Note the main point is make private members local variables as long as possible since they are accessible from the closure which C# fully supports. However as a strong-typed language, C# can't get rid of the delegate definition and the local variable definition needs to be in order within a method ('secret' has to come before 'dec').