如何为UIImageView添加标识符以跳转至对应详情视图控制器？

我有一个存储独立UIImage的数组，正通过UIImageView展示其中图片。希望为这些图片添加标识符，点击后能跳转至包含对应图片相关具体数据的视图控制器。不想用gesture.view.tag的方案，也不想创建额外视图，有没有可行的方法？

现有代码 #

class Orders2ViewController: UIViewController, OrdersBaseCoordinated {

    var orderList: [OrderInfo] = [OrderInfo( itemImage: UIImage(named: "printer.jpeg")!, itemSKU: 12567), OrderInfo(itemImage: UIImage(named: "ipad.jpeg")!, itemSKU: 34521), OrderInfo( itemImage: UIImage(named: "hoodie.jpeg")!, itemSKU: 93620)]

    lazy var someImageView: UIImageView = {
        let theImageView = UIImageView()
        let tap = UITapGestureRecognizer(target: self, action: #selector(Orders2ViewController.tappedMe))
        theImageView.addGestureRecognizer(tap)
        theImageView.isUserInteractionEnabled = true
        
        theImageView.image = orderList[selectedIndex].itemImage
        theImageView.translatesAutoresizingMaskIntoConstraints = false
        return theImageView
    }()

    @objc func tappedMe(sender: UITapGestureRecognizer)
    {
        coordinator?.passImageData(j: )
    }
}

方法1：用关联对象给UIImageView绑定数据 #

可以通过Objective-C的关联对象机制，直接给UIImageView绑定对应的OrderInfo或SKU，无需额外视图或tag。

1. 先导入objc/runtime并给UIImageView扩展关联属性：

import ObjectiveC

private var AssociatedObjectKey: UInt8 = 0

extension UIImageView {
    var associatedOrderInfo: OrderInfo? {
        get {
            return objc_getAssociatedObject(self, &AssociatedObjectKey) as? OrderInfo
        }
        set {
            objc_setAssociatedObject(self, &AssociatedObjectKey, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
    }
}

2. 创建someImageView时绑定对应的数据：

lazy var someImageView: UIImageView = {
    let theImageView = UIImageView()
    let tap = UITapGestureRecognizer(target: self, action: #selector(tappedMe))
    theImageView.addGestureRecognizer(tap)
    theImageView.isUserInteractionEnabled = true
    
    let selectedOrder = orderList[selectedIndex]
    theImageView.image = selectedOrder.itemImage
    theImageView.associatedOrderInfo = selectedOrder // 绑定对应的OrderInfo
    theImageView.translatesAutoresizingMaskIntoConstraints = false
    return theImageView
}()

3. 在点击方法中取出绑定的数据：

@objc func tappedMe(sender: UITapGestureRecognizer) {
    guard let imageView = sender.view as? UIImageView,
          let targetOrder = imageView.associatedOrderInfo else {
        return
    }
    coordinator?.passImageData(j: targetOrder.itemSKU) // 传递SKU或整个OrderInfo
}

方法2：自定义手势识别器携带数据 #

直接自定义UITapGestureRecognizer，把需要的标识符（SKU或OrderInfo）存在手势对象里，不依赖视图属性。

1. 定义自定义手势类：

class OrderTapGestureRecognizer: UITapGestureRecognizer {
    var targetSKU: Int?
    var targetOrder: OrderInfo?
}

2. 创建手势时赋值数据：

lazy var someImageView: UIImageView = {
    let theImageView = UIImageView()
    let tap = OrderTapGestureRecognizer(target: self, action: #selector(tappedMe))
    let selectedOrder = orderList[selectedIndex]
    tap.targetSKU = selectedOrder.itemSKU // 存储SKU
    tap.targetOrder = selectedOrder // 也可以存储整个OrderInfo对象
    theImageView.addGestureRecognizer(tap)
    theImageView.isUserInteractionEnabled = true
    
    theImageView.image = selectedOrder.itemImage
    theImageView.translatesAutoresizingMaskIntoConstraints = false
    return theImageView
}()

3. 在点击方法中读取手势里的数据：

@objc func tappedMe(sender: UITapGestureRecognizer) {
    guard let orderTap = sender as? OrderTapGestureRecognizer,
          let sku = orderTap.targetSKU else {
        return
    }
    coordinator?.passImageData(j: sku)
}

方法3：用闭包替代目标动作模式 #

不用目标动作模式，直接给手势绑定闭包，创建时就能直接拿到对应的数据，连点击方法都可以省略。

1. 给UITapGestureRecognizer添加闭包扩展：

extension UITapGestureRecognizer {
    convenience init(tapHandler: @escaping () -> Void) {
        self.init()
        self.addTarget(ClosureSleeve(closure: tapHandler), action: #selector(ClosureSleeve.invoke))
    }
}

class ClosureSleeve: NSObject {
    let closure: () -> Void
    
    init(closure: @escaping () -> Void) {
        self.closure = closure
        super.init()
    }
    
    @objc func invoke() {
        closure()
    }
}

2. 创建手势时直接在闭包里处理跳转：

lazy var someImageView: UIImageView = {
    let theImageView = UIImageView()
    let selectedOrder = orderList[selectedIndex]
    // 直接用闭包处理点击逻辑，上下文直接拿到selectedOrder
    let tap = UITapGestureRecognizer { [weak self] in
        self?.coordinator?.passImageData(j: selectedOrder.itemSKU)
    }
    theImageView.addGestureRecognizer(tap)
    theImageView.isUserInteractionEnabled = true
    
    theImageView.image = selectedOrder.itemImage
    theImageView.translatesAutoresizingMaskIntoConstraints = false
    return theImageView
}()

内容的提问来源于stack exchange，提问作者Tom Brooke