Is there a way to perform a chained null check in a dynamic/expando?

Question

C# has the usefull Null Conditional Operator. Well explained in this answer too.

I was wondering if it is possible to do a similar check like this when my object is

Answer 1

If you want to support this in a more natural way you can inherit from DynamicObject and provide a custom implementation:

class MyExpando : DynamicObject
    {
        private readonly Dictionary _dictionary = new Dictionary();

        public override bool TryGetMember(GetMemberBinder binder, out object result)
        {
            var name = binder.Name.ToLower();
            result = _dictionary.ContainsKey(name) ? _dictionary[name] : null;
            return true;
        }

        public override bool TrySetMember(SetMemberBinder binder, object value)
        {
            _dictionary[binder.Name.ToLower()] = value;
            return true;
        }
    }

Testing:

 private static void Main(string[] args)
        {
            dynamic foo = new MyExpando();
            if (foo.Boo?.Lol ?? true)
            {
                Console.WriteLine("It works!");
            }
            Console.ReadLine();
        }

The output will be "It works!". Since Boo does not exist we get a null reference so that the Null Conditional Operator can work.

What we do here is to return a null reference to the output parameter of TryGetMember every time a property is not found and we always return true.