public void OnNavigatedFrom(NavigationEventArgs e)
 {
 }
 public void OnNavigatedTo(NavigationEventArgs e)
 {
     // clear fragment text
     fragmentNav.BBCode = null;
 }
 private void Frame_Navigated(object sender, NavigationEventArgs e)
 {
     LogMessage("Navigated: [{0}] {1}\r\n", e.NavigationType, e.Source);
 }