Anonymous type collections?

Question

I am looking for best practices for creating collections made from anonymous types.

There are several approaches - this one and most answers on this thread assume th

Answer 1

LINQ is the way to go. Assuming you want to fetch the related objects A, B and C of every item in a collection items and sort by the related object A you would go as follows.

var relatedObjects = items.
       Select(item => new { A = item.A, B = item.B, C = item.C } ).
       OrderBy(item => item.A);

You get a collection of items of an anonymous type with the three properties A, B and C set to the related objects ordered by the related object A.

I did not verify that, but you should be able to extend the relatedObject collection later. Just do the following to add a single new item. This should work because there is only one anonymous type per assembly I think if the names and types of each property match.

relatedObjects = relatedObjects.Union(
   Enumerable.Repeat(new { A = someA, B = someB, C = someC }, 1))

Quite ugly because of the Enumerable.Repeat() but becomes quite nice if you union with a collection of new items instead of a single new item.