How to make a UIBarButtonItem perform a function when pressed? - ios

Question

I am trying to make a custom back button using this code:
let back = UIImage(named: "header_backarrow")
let backView = UIImageView(image: back)
let backItem = UIBarButtonItem(customView: backView)
navigationItem.leftBarButtonItem = backItem
I want the navigation item to perform this code:
func dismissManual() {
dismiss(animated: true, completion: nil)
}
I have tried many things like following this Stack Overflow post: Execute action when back bar button of UINavigationController is pressed
I have also tried making it a navigationItem.backBarButtonItem; however, nothing seems to work. Some things show the correct custom image, but do not work as a button; on the other hand, some work as a button, but do not show the correct image.
Does anybody know how I can show the correct image and make the item work as a button? Thanks.

Answer 1

Do it as follows:
override func viewDidLoad() {
super.viewDidLoad()
let back = UIImage(named: "header_backarrow")
let backView = UIImageView(image: back)
backView.isUserInteractionEnabled = true
let tap = UITapGestureRecognizer(target: self, action: #selector(dismissManual))
backView.addGestureRecognizer(tap)
let backItem = UIBarButtonItem(customView: backView)
navigationItem.leftBarButtonItem = backItem
}
#objc func dismissManual() {
print("print----")
// dismiss(animated: true, completion: nil)
}
Add gesture to backView it will work!
It's similiar to this question IOS - Swift - adding target and action to BarButtonItem's customView

Answer 2

Swift 4.1
The issue is that UIImage does not have tap recognition. You will have to add a tap gesture recognizer to your backView.
lazy var singleTap: UITapGestureRecognizer = {
let singleTap = UITapGestureRecognizer(target: self, action: #selector(tapDetected))
singleTap.numberOfTapsRequired = 1
return singleTap
}()
// Actions
#objc func tapDetected() {
dismiss(animated: true, completion: nil)
}
If you show your code, with some screenshots I can give more help if this doesn't solve the issue.

Answer 3

You are creating your UIBarButtonItem incorrectly. You do not need the image view.
Do it as follows:
let back = UIImage(named: "header_backarrow")
let backItem = UIBarButtonItem(image: back, style: .plain, target: self, action: #selector(dismissManual))
navigationItem.leftBarButtonItem = backItem
#objc func dismissManual() {
dismiss(animated: true, completion: nil)
}
Note that the function must be marked with #objc.
Depending on your image and how you want it displayed, you may need to create the image as follows:
let back = UIImage(named: "header_backarrow").withRenderingMode(.alwaysOriginal)
Another option is to create a UIButton with the image and setup to call your dismissManual function. Create the UIBarButtonItem with the button as the custom view.
But it's easier to create a standard UIBarButtonItem when all you have is a simple image or a simple string.

Answer 4

let barButtonItem = UIBarButtonItem(image: UIImage(named: "backImgs"),
style: .plain,
target: self,
action: #selector(menuButtonTapped))
// Adding button to navigation bar (rightBarButtonItem or leftBarButtonItem)
self.navigationItem.rightBarButtonItem = barButtonItem
// Private action
#objc fileprivate func menuButtonTapped() { // body method here }
Check out this, it may help Thanks.