title: share access toke on xamarin forms
body: <p>I Have xamarin forms application, authenticate with asp.net membership and give accesstoken after authenticate.
  In other platforms (ex silverlight, javascrip libs ....), this token access shared accross all requests to server (ex webclient,httpclient, image source request and ...) and all requests send it to server automaticaly
  how can I share this token on xamarin forms for all requests?
  I cant set cookies for all requests handly. because some of them like imagesource does not have any way to set it</p>