One of the nice things about object oriented programming is the ability to add capabilities to objects to suit your needs. I've extended my own classes before, but one thing I had not done was create an extension for a standard class.
Today I found myself wishing that the Dictionary class had a Prepend method so I could add something to the front of the list easily. Like most developers, I did some looking on the internet to see if anyone else had created something like what I was wanting, plus looking for just general examples. I found nothing of the former, but plenty of the latter. One really nice example was found here (http://gltaurus.blogspot.com/2010/07/dictionary-class-extensions-copyto-sort.html) from a couple of years ago. Using that as a nice guideline, I created this:
public static class DictionaryExtensions
public static void Prepend<T, V>(this Dictionary<T, V> source,
T newKey, V newValue)
// load existing dictionary into temporary list
List<KeyValuePair<T, V>> entries = new List<KeyValuePair<T, V>>(source);
// clear source
// add the new item to source
// now add the original values back into the dictionary
foreach (var item in entries)
It's a very simple solution, but it makes the class very usable for what I needed: adding a default selection for dropdowns. My repository methods return a Dictionary with available key/values. Anyways, I know this is nothing new to those of you more experienced than I, but it was nice to do.