iOS set toolbar items from nav controller subclass

Question

I have subclassed my UINavigationController and am trying to set the toolbar items but they are not appearing. I have set the class in storyboard for the nav controller. In the view controllers, I set [self.navigationController setToolBarHidden:NO animated:NO] in the viewDidAppear method. Below is my code I am using in the subclass. Any help would be great thanks.

@interface FCMapNavigationController ()

@end

@implementation FCMapNavigationController

- (void)viewDidLoad
{
    // Call super
    [super viewDidLoad];

    NSLog(@"Toolbar = %@", self.toolbar);

    // Set the toolbar items
    UISegmentedControl *segment = [[UISegmentedControl alloc] initWithItems:@[@"Standard", @"Satellite", @"Hybrid", @"Terrain"]];
    //[segment addTarget:self action:@selector(changeMapType:) forControlEvents:UIControlEventValueChanged];
    //[segment setSelectedSegmentIndex:self.mapView.mapType - 1];
    UIBarButtonItem *seg = [[UIBarButtonItem alloc] initWithCustomView:segment];
    UIBarButtonItem *flex = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
    //self.refresh = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh target:self action:@selector(refreshData)];
    [self setToolbarItems:@[flex, seg, flex]];
}

@end

Answer 1

The only UIViewController can affect toolbar items. So you can workaround like that:

class NavigationController: UINavigationController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        self.topViewController.setToolbarItems([/*your items*/], animated: false)
    }

}