How to create own dynamic type or dynamic object in C#?

c# dynamic viewbag
Dmytro picture Dmytro · Oct 3, 2012 · Viewed 212.6k times · Source

There, is for example, ViewBag property of ControllerBase class and we can dynamically get/set values and add any number of additional fields or properties to this object, which is cool .I want to use something like that, beyond MVC application and Controller class in other types of applications. When I tried to create dynamic object and set it's property like below:

1. dynamic MyDynamic = new { A="a" };
2. MyDynamic.A = "asd";
3. Console.WriteLine(MyDynamic.A);

I've got RuntimeBinderException with message Property or indexer '<>f__AnonymousType0.A' cannot be assigned to -- it is read only in line 2. Also I suggest It's not quite what I'm looking-for. Maybe is there some class which can allow me to do something like:

??? MyDynamic = new ???();
MyDynamic.A = "A";
MyDynamic.B = "B";
MyDynamic.C = DateTime.Now;
MyDynamic.TheAnswerToLifeTheUniverseAndEverything = 42;

with dynamic adding and setting properties.

Answer

Mario S picture Mario S · Oct 3, 2012 
dynamic MyDynamic = new System.Dynamic.ExpandoObject();
MyDynamic.A = "A";
MyDynamic.B = "B";
MyDynamic.C = "C";
MyDynamic.Number = 12;
MyDynamic.MyMethod = new Func<int>(() => 
{ 
    return 55; 
});
Console.WriteLine(MyDynamic.MyMethod());

Read more about ExpandoObject class and for more samples: Represents an object whose members can be dynamically added and removed at run time.

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