Answer by Sinatr for How to lazily evaluate C# anonymous class property

Rather than storing result as object, why not storing lambda, which retreives it?

Change

var obj = new { Number = GetNum() };DoSomeWork();Serialize(obj);

to

var lazy = () => new { Number = GetNum() }; // lambdaDoSomeWork();Serialize(lazy()); // invoke it or not

Fiddle.Note: I make your initial code compilable and returning wrong result.