ios - viewWillAppear、viewDidAppear が pushViewController で呼び出されない

Question

NewViewController_iPhone *newViewController = [[NewViewController_iPhone alloc] initWithNibName:@"NewViewController_iPhone" bundle:nil];


[self.navigationController pushViewController:newViewController animated:YES];

viewWillAppear:でviewDidAppear:呼び出されませんNewViewController_iPhone。なぜだめですか？