/// <summary>
/// Permet de gérer l'état de navigation à l'instant T pour un ViewModel
/// </summary>
/// <param name="viewModelFromName">ViewModel pris en compte</param>
private void SetNavigationHistory(Type viewModelFromName)
{
if (!_historyNavigation.ContainsKey(viewModelFromName))
{
#if WINDOWS_PHONE
_historyNavigation.Add(viewModelFromName, _rootFrame.CurrentSource);
#else
_historyNavigation.Add(viewModelFromName, _rootFrame.GetNavigationState());
#endif
}
}