swift - 在 swift 4 中调配方法

Question

<分区>

Answer 1

initialize() 不再公开:Method 'initialize()' 定义了 Objective-C 类方法 'initialize'，这是 Swift 不允许的

所以现在的方法是通过公共(public)静态方法运行您的 swizzle 代码。

例如

在扩展中: (该扩展用于kickstarted开源代码:https://github.com/kickstarter/ios-oss/blob/master/Library/DataSource/UIView-Extensions.swift)

private var hasSwizzled = false

extension UIView {
    final public class func doBadSwizzleStuff() {
        guard !hasSwizzled else { return }

        hasSwizzled = true
        swizzle(self) /* This is pseudo - run your method here */
    }
}

在应用委托(delegate)中: (kickstarted开源代码中使用了该方法:https://github.com/kickstarter/ios-oss/blob/7c827770813e25cc7f79a28fa151cd713efe936f/Kickstarter-iOS/AppDelegate.swift#L33)

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: UIApplicationLaunchOptionsKey: Any]?) -> Bool 
{
    UIView.doBadSwizzleStuff()
}

---

另一种方法是使用单例:

extension UIView {
    static let shared : UIViewController = {
        $0.initialize()
        return $0
    }(UIViewController())

    func initialize() {
        // make sure this isn't a subclass
        guard self === UIViewController.self else { return }

        let swizzleClosure: () = {
            UIViewController().swizzle() /* This is pseudo - run your method here */
        }()
        swizzleClosure
    }
}

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: UIApplicationLaunchOptionsKey: Any]?) -> Bool 
{
    _  = UIViewController.shared
}