Anonymous Types - Dynamic Programming With C#

In a previous post I discussed trying to work with Anonymous types in .NET. I had included some code for working with those types to try and make it easier to pass your information around inside your projects.

Essentially, it was a wrapper for Reflection that allowed you to access properties by providing the correct type and property name. It would keep the instance of the Anonymous type in memory so it could work directly with the object.

You may have noticed that there was .Get() functions, but no .Set() function. Why is that?

You may have never noticed this before, but all of the properties in an Anonymous type are read-only. Most of the time you aren't going to make changes to those values anyways, but if you can't assign the value of a property in one pass, then it's a bummer.

For fun, I took a little time to write another version of AnonymousType. This one is a lot more flexible than the one before, but you aren't really using C# the way it was intended to be. Instead of using reflection you're using a Dictionary, specifically with strings (for the property names) and objects (for the values).

You create objects the same way as before, but now you have access to a few more features and functions.

//Creating Instances of AnonymousType
//Create a using an Anonymous type
AnonymousType type = AnonymousType.Create(new {
  name = "Jim",
  age = 40
  //method = ()=> { Console.WriteLine(); } // still doesn't work here

//or an empty AnonymousType
AnonymousType empty = new AnonymousType();

//or even an existing object
var something = new {
  name = "Mark",
  age = 50
AnonymousType another = new AnonymousType(something);

//Creating And Using Methods
//append methods and call them
another.SetMethod("print", (string name, int age, bool admin) => {
  Console.WriteLine("{0} :: {1} :: {2}", name, age, admin);
another.Call("print", "Mark", 40, false);

//append a method with a return value
another.SetMethod("add", (int a, int b) => {
  return a + b;
int result = empty.Call<int>("add", 5, 10);

//Working With Multiple Properties
//add properties and work with them (NOTE: a better way is shown below)
another.Set("list", new List<string>());
another.Get<List<string>>("list").Add("String 1");
another.Get<List<string>>("list").Add("String 2");
another.Get<List<string>>("list").Add("String 3");

//or use it an easier way
another.With((List<string> list) => {
  list.Add("String 4");
  list.Add("String 5");
  list.Add("String 6");

//you can work with more than one type
another.With((string name, int age) => {
  Console.Write("{0} :: {1}", name, age);

Again, this is breaking away from the way C# was intended to be used, so be careful how much you make use of it. For the most part you're going to want to create your own classes to hold this information, but while working with Anonymous types, this is a quick and easy way to pass your information around.

May 28, 2009

Anonymous Types - Dynamic Programming With C#

Post titled "Anonymous Types - Dynamic Programming With C#"