带闭包的UIGestureRecognizer

我有视图，我想在其中执行向右滑动手势。 不幸的是我收到错误EXC_BAD_ACCESS。 有人知道这里有什么问题吗？ 请看下面的代码。

extension UIView { func addGestureRecognizerWithAction(nizer: UIGestureRecognizer, action:() -> ()) { class Invoker { var action:() -> () init(action:() -> ()) { self.action = action } func invokeTarget(nizer: UIGestureRecognizer) { self.action() println("Hi from invoker") } } addGestureRecognizer(nizer) nizer.addTarget(Invoker(action), action: "invokeTarget:") } } class BugView: UIView { override func awakeFromNib() { super.awakeFromNib() var swipeRight = UISwipeGestureRecognizer() swipeRight.direction = UISwipeGestureRecognizerDirection.Right self.addGestureRecognizerWithAction(swipeRight) { println("Hi from the gesture closure") } } } 

Answer 1

最后返回true是对的。 在他上面的回答中，他指出我正确的方向，建议让Invoker成为NSObject的子类。

但这不是我在代码中唯一的错误。 我发现当滑动发生时，旨在处理事件的Invoker对象已经从内存中消失了。 我认为关闭它的提法并没有像它应该的那样被捕获。 现在我想出了另一种实现此function的方法，我想与您分享：

 class UIGestureRecognizerWithClosure: NSObject { // must subclass NSObject otherwise error: "class does not implement methodSignatureForSelector: -- " !! var closure:() -> () init(view:UIView, nizer: UIGestureRecognizer, closure:() -> ()) { self.closure = closure super.init() view.addGestureRecognizer(nizer) nizer.addTarget(self, action: "invokeTarget:") } func invokeTarget(nizer: UIGestureRecognizer) { self.closure() } } 

此代码段显示了如何使用代码：

 var swipeRight = UISwipeGestureRecognizer() swipeRight.direction = UISwipeGestureRecognizerDirection.Right // swipeWrapper has to be defined as a property: var swipeWrapper:UIGestureRecognizerWithClosure? // -> this is needed in order to keep the object alive till the swipe event occurs swipeWrapper = UIGestureRecognizerWithClosure(view: self, nizer:swipeRight) { println("Hi from the gesture closure") } 

Answer 2

老兄，这是UIGestures的ClosureActionsHandler。 我已经为UIView扩展了这个，所以你可以在所有UIComponents上实现。 这就是Git-link 。 快乐的编码令人敬畏的极客。

 import Foundation import UIKit private var AssociatedObjectHandle: UInt8 = 25 public enum closureActions : Int{ case none = 0 case tap = 1 case swipe_left = 2 case swipe_right = 3 case swipe_down = 4 case swipe_up = 5 } public struct closure { typealias emptyCallback = ()->() static var actionDict = [Int:[closureActions : emptyCallback]]() static var btnActionDict = [Int:[String: emptyCallback]]() } public extension UIView{ var closureId:Int{ get { let value = objc_getAssociatedObject(self, &AssociatedObjectHandle) as? Int ?? Int() return value } set { objc_setAssociatedObject(self, &AssociatedObjectHandle, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC) } } public func actionHandleBlocks(_ type : closureActions = .none,action:(() -> Void)? = nil) { if type == .none{ return } var actionDict : [closureActions : closure.emptyCallback] if self.closureId == Int(){ self.closureId = closure.actionDict.count + 1 closure.actionDict[self.closureId] = [:] } if action != nil { actionDict = closure.actionDict[self.closureId]! actionDict[type] = action closure.actionDict[self.closureId] = actionDict } else { let valueForId = closure.actionDict[self.closureId] if let exe = valueForId![type]{ exe() } } } @objc public func triggerTapActionHandleBlocks() { self.actionHandleBlocks(.tap) } @objc public func triggerSwipeLeftActionHandleBlocks() { self.actionHandleBlocks(.swipe_left) } @objc public func triggerSwipeRightActionHandleBlocks() { self.actionHandleBlocks(.swipe_right) } @objc public func triggerSwipeUpActionHandleBlocks() { self.actionHandleBlocks(.swipe_up) } @objc public func triggerSwipeDownActionHandleBlocks() { self.actionHandleBlocks(.swipe_down) } public func addTap(Action action:@escaping() -> Void){ self.actionHandleBlocks(.tap,action:action) let gesture = UITapGestureRecognizer() gesture.addTarget(self, action: #selector(triggerTapActionHandleBlocks)) self.isUserInteractionEnabled = true self.addGestureRecognizer(gesture) } public func addAction(for type: closureActions ,Action action:@escaping() -> Void){ self.isUserInteractionEnabled = true self.actionHandleBlocks(type,action:action) switch type{ case .none: return case .tap: let gesture = UITapGestureRecognizer() gesture.addTarget(self, action: #selector(triggerTapActionHandleBlocks)) self.isUserInteractionEnabled = true self.addGestureRecognizer(gesture) case .swipe_left: let gesture = UISwipeGestureRecognizer() gesture.direction = UISwipeGestureRecognizerDirection.left gesture.addTarget(self, action: #selector(triggerSwipeLeftActionHandleBlocks)) self.isUserInteractionEnabled = true self.addGestureRecognizer(gesture) case .swipe_right: let gesture = UISwipeGestureRecognizer() gesture.direction = UISwipeGestureRecognizerDirection.right gesture.addTarget(self, action: #selector(triggerSwipeRightActionHandleBlocks)) self.isUserInteractionEnabled = true self.addGestureRecognizer(gesture) case .swipe_up: let gesture = UISwipeGestureRecognizer() gesture.direction = UISwipeGestureRecognizerDirection.up gesture.addTarget(self, action: #selector(triggerSwipeUpActionHandleBlocks)) self.isUserInteractionEnabled = true self.addGestureRecognizer(gesture) case .swipe_down: let gesture = UISwipeGestureRecognizer() gesture.direction = UISwipeGestureRecognizerDirection.down gesture.addTarget(self, action: #selector(triggerSwipeDownActionHandleBlocks)) self.isUserInteractionEnabled = true self.addGestureRecognizer(gesture) } } }