public MainVM()
 {
     model = new Model();
     Pages.SetModel(model);
     CurrentPage = Pages.GetPageByType(PageType.StudentList);
     Pages.CurrentPageChanged += PageContainer_CurrentPageChanged;
 }
 void PageContainer_CurrentPageChanged(object sender, PageType e)
 {
     CurrentPage = Pages.GetPageByType(e);
     NotifyPropertyChanged("CurrentPage");
 }