See the new official way here: http://motzcod.es/post/113280718807/official-pull-to-refresh-in-xamarinforms-140
For the latest code and other new awesome controls see my new repo: https://github.com/jamesmontemagno/Xamarin.Forms-Awesome-Controls
Implementation of pull to refresh for Xamarin.Forms ListView
Here is my blog post: http://motzcod.es/post/87917979362/pull-to-refresh-for-xamarin-forms-ios
