title: Sorting a composite collection
body: <p>So WPF doesn't support standard sorting or filtering behavior for views of CompositeCollections, so what would be a best practice for solving this problem. </p>
  
  <p>There are two or more object collections of different types. You want to combine them into a single sortable and filterable collection (withing having to manually implement sort or filter).</p>
  
  <p>One of the approaches I've considered is to create a new object collection with only a few core properties, including the ones that I would want the collection sorted on, and an object instance of each type. </p>
  
  <pre><code>class MyCompositeObject
  {
      enum           ObjectType;
      DateTime       CreatedDate;
      string         SomeAttribute;
      myObjectType1  Obj1;
      myObjectType2  Obj2;
  {
  class MyCompositeObjects : List&lt;MyCompositeObject&gt; { }
  </code></pre>
  
  <p>And then loop through my two object collections to build the new composite collection. Obviously this is a bit of a brute force method, but it would work. I'd get all the default view sorting and filtering behavior on my new composite object collection, and I'd be able to put a data template on it to display my list items properly depending on which type is actually stored in that composite item.</p>
  
  <p>What suggestions are there for doing this in a more elegant way?</p>