public AddingMachinePage(AdderViewModel viewModel)
{
InitializeComponent();
// Set ViewModel as BindingContext.
BindingContext = viewModel;
}
public App()
{
// Instantiate and initialize ViewModel for page.
adderViewModel = new AdderViewModel();
adderViewModel.RestoreState(Current.Properties);
MainPage = new AddingMachinePage(adderViewModel);
}