Swift: Terminating app UITapGestureRecognizer for nib class - swift

Question

I create nib class :
import UIKit
class AlertController: UIView {
#IBOutlet weak var back: UIView!
#IBOutlet weak var viewMain: UIView!
class func createAlert() -> AlertController {
let myNib = UINib(nibName: "Alert", bundle: nil)
let nib = myNib.instantiate(withOwner: nil, options: nil)[0] as! AlertController
nib.back.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleBack(sender:))))
return nib
}
#objc func handleBack(sender: UITapGestureRecognizer) {
//viewMain.isHidden = true
print("LogIos => X")
}
}
And use it on another class :
let view = AlertController.createAlert()
viewMain.addSubview(view)
This work fine, but if i click on back button i get below error:
2018-06-13 12:28:03.958448+0430 Mat[50493:243526] *** Terminating
app due to uncaught exception 'NSInvalidArgumentException', reason:
'+[Mat.AlertController handleBackWithSender:]: unrecognized selector
sent to class 0x104db4e90'
But if i use below code, work fine:
#IBAction func xxx(_ sender: Any) {
print("LogIos => Y")
}
I want use UITapGestureRecognizer because i use View for custom button

Answer 1

Although I do not understand what you mean with "func xxx works fine" (which should not, if you use the same code as above), the problem is that:
createAlert is a static (class) function
Inside
you create an instance nib of your AlertController
your #selector refers to self, which in this case is the class itself, not the instance
Therefore, the gesture recognizer refers to the static (class) function handleBack - which you can see when you take a close look at + sign in the exception text:
reason: '+[Mat.AlertController handleBackWithSender:]: unrecognized selector
Therefore, either make handleBack a static (class func), or provide an instance to as the target (which is what you want, as I would assume)
So
nib.back.addGestureRecognizer(UITapGestureRecognizer(target: nib, action: #selector(handleBack(sender:))))
should work for you.
Remark
Nevertheless, let me allow you a design hint: Although you name it AlertController, it is not a view controller, but a UIView - this is confusing. You should clearly separate view and controller, and separate which of those handles what.