title: Xamarin.Forms Carousel Page Swipe Event Page Changing
body: <p>I'm using the Carousel Page that ships with Xamarin Form (2.5.0) and would like to be able to detect when a page is about to change.</p>
  
  <p>Each Page has some validation and if this fails I want to prevent the user from moving to the next page.  Currently the only event I can see is PageChanged and this is where I trigger the validation, however the user must swipe back to see the error message.</p>
  
  <p>Is there a way to hook into the native swipe event?</p>
  
  <p>The App is currently targeting iOS, however it will eventually need to support Android.</p>