Add badges Count in the navigation bar using Xamarin Forms

Hello,

i am very new to xamarin platform working on IOS & Android App in Xamarin.Forms.

i wanted to add notification as badges count in the navigation

i am using xamarin forms. i even tried below example
https://social.technet.microsoft.com/wiki/contents/articles/37733.xamarin-shopping-cart-counter-in-forms-navigation-bar.aspx
but my App crashing...its not at all working properly.

please help me out with tested working example in forms...

Thanks in advance