iOS / Swift Can't add gesture to child class - ios

Question

I'm writing an child class but couldn't add gesture recognize for it.
Selector error. Here is my code:
import UIKit
class Alert: KeyboardViewController {
var AlertContainer = UIView()
func ShowAlert(message: String,view: UIView)
{
var tap = UITapGestureRecognizer(target: self, action:Selector("CloseAlertView"))
tap.numberOfTapsRequired = 1
AlertContainer.addGestureRecognizer(tap)
AlertContainer.setTranslatesAutoresizingMaskIntoConstraints(false)
AlertContainer.userInteractionEnabled = true
AlertContainer.backgroundColor = UIColor(rgb: 0x000000, alpha: 0.8)
view.addSubview(AlertContainer)
var CTop = NSLayoutConstraint(item: AlertContainer, attribute: .Top, relatedBy: .Equal, toItem: view, attribute: .Top, multiplier: 1.0, constant: 0.0)
var CRight = NSLayoutConstraint(item: AlertContainer, attribute: .Right, relatedBy: .Equal, toItem: view, attribute: .Right, multiplier: 1.0, constant: 0.0)
var CLeft = NSLayoutConstraint(item: AlertContainer, attribute: .Left, relatedBy: .Equal, toItem: view, attribute: .Left, multiplier: 1.0, constant: 0.0)
var CBottom = NSLayoutConstraint(item: AlertContainer, attribute: .Bottom, relatedBy: .Equal, toItem: view, attribute: .Bottom, multiplier: 1.0, constant: 0.0)
view.addConstraints([CTop,CRight,CLeft,CBottom])
}
func CloseAlertView() {
AlertContainer.removeFromSuperview()
}
}
But when i tap on to this view, error: exc_bad_access or some time unrecognized selector sent to instance. Really don't know why ?
and one more question that i can't access to parent class view by super.view ?

Answer 1

Are you are calling this class in the following way (if not ignore my answer)?
// wrong implementation
func myFunc() {
var a = Alert()
a.ShowAlert("Message", view: view)
}
The previous code is wrong (and causes BAD_ACCESS) because a does not exists anymore after the function finished. So when the gesture is fired, it acts on nothing and crashes.
Solution:
var a = Alert() // a property of the caller class
func myFunc() {
a.ShowAlert("Message", view: view)
}
In this way the life of a is long enough to wait for the gesture.