UIBarButtonItem not Showing - ios

Question

So Im trying to create a UIBarButtonItem with a custom UIView by subclassing it like so.
import UIKit
import SnapKit
class LocationManager: UIBarButtonItem {
let createdView = UIView()
lazy var currentCityLabel: UILabel = {
let currentCityLabel = UILabel()
currentCityLabel.text = "Philadelphia, PA"
guard let customFont = UIFont(name: "NoirPro-SemiBold", size: 20) else {
fatalError("""
Failed to load the "CustomFont-Light" font.
Make sure the font file is included in the project and the font name is spelled correctly.
"""
)
}
currentCityLabel.adjustsFontForContentSizeCategory = true
return currentCityLabel
}()
lazy var downArrow: UIImageView = {
let downArrow = UIImageView()
downArrow.contentMode = .scaleAspectFit
downArrow.image = UIImage(named: "downArrow")
return downArrow
}()
override init() {
super.init()
setupViews()
}
#objc func setupViews(){
customView = createdView
createdView.addSubview(currentCityLabel)
currentCityLabel.snp.makeConstraints { (make) in
make.left.equalTo(createdView.snp.left)
make.top.bottom.equalTo(createdView)
}
createdView.addSubview(downArrow)
downArrow.snp.makeConstraints { (make) in
make.left.equalTo(currentCityLabel.snp.right).offset(5)
}
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
However, when I create it and assign it in my viewController I see nothing
import UIKit
class ViewController: UICollectionViewController {
override func viewDidLoad() {
super.viewDidLoad()
setupViews()
}
#objc func setupViews(){
guard let collection = collectionView else {
return
}
collection.backgroundColor = .white
let customLeftBar = LocationManager()
self.navigationController?.navigationItem.leftBarButtonItem = customLeftBar
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
I've looked at other post and none seem to quite match my situation. I'm beginning to think it is because I didn't give the UIView a frame but I am not exactly sure how I would do that in this instance if that is the case. Anyone see anything I don't that could potentially help me solve this problem. Also setting a target doesn't work I tried two different ways and none of them triggers a thing
#objc func setupBarButtonItems(){
let customLeftBar = LocationManager()
customLeftBar.action = #selector(self.leftBarPressed)
customLeftBar.target = self
customLeftBar.customView?.isUserInteractionEnabled = true
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(self.leftBarPressed))
customLeftBar.customView?.addGestureRecognizer(tapGesture)
navigationItem.leftBarButtonItem = customLeftBar
}
#objc func leftBarPressed(){
print("left bar tapped")
}

Answer 1

Change your adding line from
self.navigationController?.navigationItem.leftBarButtonItem = customLeftBar
to
self.navigationItem.leftBarButtonItem = customLeftBar
When add the barItem, you need to add it via navigationItem of the ViewController, not NavigationController
EDITED for add the action
Your custom UIBarButtonItem is a Custom View's BarButtonItem, so the target and selector will not working.
You can add your custom action by adding a button into your customView, and send the action via closure
Init your closure
var didSelectItem: (() -> Void)?
Add the create button code in your #objc func setupViews()
let button = UIButton(type: .custom)
createdView.addSubview(button)
button.snp.makeConstraints { (maker) in
maker.top.bottom.leading.trailing.equalTo(createdView)
}
// button.backgroundColor = UIColor.cyan // uncomment this line for understand about the barbuttonitem's frame
button.addTarget(self, action: #selector(didTap(_:)), for: .touchUpInside)
and add the function
#objc func didTap(_ button: UIButton) {
print("Did tap button")
}
In your viewController, you can get the tap action by
customLeftBar.didSelectItem = { [weak self] in
self?.leftBarPressed()
}
Unfortunately, your barbuttonitem's default frame is 30x30, so you must be set the frame for your barbuttonitem. If not, you can only catch the tap action in 30x30 area (uncomment the code for see it)