UIButton block equivalent to addTarget:action:forControlEvents: method?

Question

I looked around, but couldn\'t find this on the internet, nor anywhere in the Apple docs, so I\'m guessing it doesn\'t exist.

But is there a iOS4 blocks equivalent A

Answer 1

Swift 4

Here is the swift solution

class ClosureSleeve {
let closure: () -> ()

init(attachTo: AnyObject, closure: @escaping () -> ()) {
    self.closure = closure
    objc_setAssociatedObject(attachTo, "[\(arc4random())]", self, .OBJC_ASSOCIATION_RETAIN)
}

@objc func invoke() {
    closure()
  }
}

extension UIControl {
func addAction(for controlEvents: UIControlEvents = .primaryActionTriggered, action: @escaping () -> ()) {
    let sleeve = ClosureSleeve(attachTo: self, closure: action)
    addTarget(sleeve, action: #selector(ClosureSleeve.invoke), for: controlEvents)
 }
}

Example Usage:

button.addAction {
print("button pressed")
}