How to Hide a Toolbar on iOS Devices

// in a UIViewController subclass
- (void)viewWillAppear:(BOOL)animated {
    [self.navigationController setToolbarHidden:NO animated:YES];
    [super viewWillAppear:animated];
}
- (void)viewWillDisappear:(BOOL)animated {
    [self.navigationController setToolbarHidden:YES animated:YES];
    [super viewWillDisappear:animated];
}