jeffwilcox/wp-thememanager — pull request #21 by jlaanstra (2014-09-16 09:56:52+00:00)
Title: Do not throw when the theme is not in the MergedDictionaries.

This PR fixes an issue where a custom theme is not applied if the ResourceDictionary is not included in the MergedDictionaries section in app.xaml.

The `Single()` throws if it does not find a single ResourceDictionary with the specified Uri, so `FirstOrDefault()` would be a better option.