Question

I have class method:

public object MyMethod(object obj)
{
   // I want to add some new properties example "AddedProperty = true"
   // What must be here?
   // ...

   return extendedObject;
}

And:

var extendedObject = this.MyMethod( new {
   FirstProperty = "abcd",
   SecondProperty = 100 
});

Now the extendedObject has new properties. Help please.

Answer 1

You can’t do that.

If you want a dynamic type that you can add members to at runtime then you could use an ExpandoObject.

Represents an object whose members can be dynamically added and removed at run time.

This requires .NET 4.0 or newer.