title: Download a file from a link on a WPF Browser Application application
body: <p>How do I download a file from a link on a 
  WPF Browser Application application, I am using 
  the method NavigationService.Navigate(http://www.google.com/docs/Arquivo.xlsx ") Works for download window opens but after that 
  download was completed or canceled I can not 
  but enter navigate the pages using method 
  NavigationService.Navigate, I noticed that the 
  Content property of NavigationService is null 
  when I navigate to a file path, someone 
  know what's going on?</p>