SWIFT | Personalizzare pulsante back in Navigation Controller

override func viewDidLoad() { super.viewDidLoad() let _btBack = UIButton(type: .Custom) _btBack.addTarget(self, action: "returnToRoot:", forControlEvents: UIControlEvents.TouchUpInside) _btBack.setImage(UIImage(named: "arrow-left")?.imageWithRenderingMode(.AlwaysTemplate), forState: .Normal) _btBack.imageView?.tintColor = UIColor.whiteColor() _btBack.sizeToFit() self.navigationItem.leftBarButtonItem = UIBarButtonItem(customView: _btBack) self.navigationController?.setNavigationBarHidden(false, animated:true) }…