private void MaterialSubPage_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
 {
     ViewModel = DataContext as MaterialSubPageViewModel;
     if (ViewModel != null)
     {
         ViewModel.Parameter = this.Tag;
     }
 }
 private void MaterialSubPage_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
 {
     ViewModel = DataContext as MaterialSubPageViewModel;
     if (ViewModel != null)
     {
         ViewModel.Parameter = this.Tag;
     }
 }