Creating a custom back button across my app - ios

Question

I’m trying to change the default look of Navigation Controller back button across my app.
I would like to use and image(icon) and remove the “Back” text.
This code stretched the image across the button and does not remove the button title.
let backImg: UIImage = UIImage(named: "icon_back")!
UIBarButtonItem.appearance().setBackButtonBackgroundImage(backImg, for: .normal, barMetrics: .default)
An recommendation how to do is inside AppDelegate (didFinishLaunchingWithOptions)?

Answer 1

The easy way of doing is just create one BaseViewController for your project which is derived from UIViewController. You can have on common method in BaseViewController to create your custom leftBarButton in every viewController. The remaining viewController in your project should be derived from this BaseViewController,
class BaseViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
createLeftBarButton(image: #Pass image here#, width: #Pass width of your image view#) // Create custom back bar button.
}
/**Create cutom back bar button*/
func createLeftBarButton(image: UIImage?, width: CGFloat) {
let backButton: UIButton = UIButton(frame: CGRect(x: 0, y: 0, width: width, height: 50))
backButton.imageView?.contentMode = .scaleAspectFill
backButton.imageView?.bounds = CGRect(x: 0, y: 0, width: width, height: width)
backButton.setImage(image, for: .normal)
backButton.setImage(image, for: .highlighted)
backButton.addTarget(self, action: #selector(leftBarButtonItemPressed(_:)), for: .touchUpInside)
let leftItem: UIBarButtonItem = UIBarButtonItem(customView: backButton)
navigationItem.leftBarButtonItem = leftItem
}
/**Custom back bar button pressed. So handle here*/
func leftBarButtonItemPressed(_ sender: UIButton) {
view.endEditing(true) // End editing if any.
if isViewControllerPresented() { // Check view controller is presented or pushed
dismiss(animated: true, completion: nil) // Dismiss ViewController if presented
} else {
_ = navigationController?.popViewController(animated: true) // Pop ViewController if pushed
}
}
/**To check whether view controller is presented or pushed.*/
func isViewControllerPresented() -> Bool {
if self.presentingViewController?.presentedViewController == self {
return true
}
if (self.navigationController != nil && self.navigationController?.presentingViewController?.presentedViewController == self.navigationController) && self.navigationController?.viewControllers.count == 1 {
return true
}
if self.tabBarController?.presentingViewController is UITabBarController {
return true
}
return false
}
}
// Sub class your remaining viewControllers like this.
class FirstViewController: BaseViewController {
override func viewDidLoad() {
super.viewDidLoad() // When calling this super method, the custom back bar button will be created for you
}
}
Thanks.

Answer 2

You can doing this by setting the navigationItem's BackButtonBackgroundImage;
also you can set the appearance for global effect:
let item = UIBarButtonItem.appearance(whenContainedInInstancesOf: [UINavigationBar.self])
item.setBackButtonBackgroundVerticalPositionAdjustment(-10, for: .default) item.setBackButtonBackgroundImage(youImage, for: .normal, barMetrics: .default)
for removing the back title, you can do like this:
#implementation UINavigationItem (BackItem)
-(UIBarButtonItem *)backBarButtonItem {
UIBarButtonItem *item = [[UIBarButtonItem alloc] initWithTitle:#" " style:UIBarButtonItemStylePlain target:nil action:nil];
item.tintColor = [UIColor darkGrayColor];
return item;
}
#end