The shortest blog post ever. If you want to URLEncode (or decode) in a Xamarin Forms PCL, simply use:
var encoded = System.Net.WebUtility.UrlEncode(veryUnEncoded);
There is also methods for HTML encoding and decoding in there and url encoding/decoding to bytes. I always have to look this up for some reason, that's why I'm putting it on my blog so that I can find it easily.
Thank you, that is all...