UIbutton inside UIViewControllers inside UIScrollView not getting triggered on touch - ios

Question

I'v added two UIViewControllers inside of a UIScrollView, and now I'm trying to add targets to the button inside of the UIViewControllers, I've checked the internet but none of those solutions worked for me, this is what I'm doing
inside of the main ViewController
scrollView.contentSize = CGSize(width: view.frame.width * 2, height:0)
let postsViewController = PostsViewController()
postsViewController.scrollView = scrollView
postsViewController.view.frame = CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height)
let chatsViewController = ChatsViewController()
chatsViewController.scrollView = scrollView
chatsViewController.view.frame = CGRect(x: view.frame.width, y: 0, width: view.frame.width, height: view.frame.height)
scrollView.addSubview(postsViewController.view)
scrollView.addSubview(chatsViewController.view)
postsViewController.didMove(toParent: self)
chatsViewController.didMove(toParent: self)
then inside the postsViewController I'm doing this
let a = UIButton()
a.setImage(currentTheme.chat, for: .normal)
a.imageEdgeInsets = UIEdgeInsets(top: 1.5, left: 0.0, bottom: 1.5, right: 0.0)
view.addSubview(a)
view.addConstraint("V:|-200-[v0(80)]-0-|",a)
view.addConstraint("H:|-200-[v0(80)]-0-|",a)
a.addTarget(self, action: #selector(abc), for: .touchUpInside)
the add "addConstraint" is an extension function just to add constraint to views
the abc function
#objc func abc() {
print("hello")
}
you can see the scrollView setting here
https://ibb.co/ZB1LJsy

Answer 1

Try to initialize your button like this
let a : UIButton = UIButton(type: .custom)
And add this after to the initialize of your UIScrollView
scrollView.delaysContentTouches = false

Answer 2

I tested in an xcode project. I can not execute the function (button) in the other UIViewController.
By cons if you sent the #selector it works.
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let scrollView : UIScrollView = UIScrollView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.width))
scrollView.delaysContentTouches = false
view.addSubview(scrollView)
let TestViewController = TestViewController1()
TestViewController.select = #selector(demande(sender:))
TestViewController.view.frame = CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height)
scrollView.addSubview(TestViewController.view)
print("dd")
}
#objc func demande(sender: UIButton!) {
print("button click", sender.tag)
}
}
class TestViewController1: UIViewController {
var select : Selector!
override func viewDidLoad() {
super.viewDidLoad()
let button : UIButton = UIButton(type: .custom)
button.setImage(#imageLiteral(resourceName: "turn_off_on_power-512"), for: .normal)
button.tag = 2
button.addTarget(self, action: select, for: .touchUpInside)
button.frame = CGRect(x: 0, y: 0, width: 200, height: 200)
view.addSubview(button)
}
}
Hoping that it helps you

Answer 3

okay, I solved my problem, the reason why the button wasn't getting trigger is because I forgot to attach the viewController of the view to the scrollview, so all I had to do is to attach the viewController as well and it worked.
self.addChild(postsViewController)
self.addChild(chatsViewController)
now it is working.