ios - 在 Swift 3.1 中调配 CocoaTouch 类

Question

我在 XCode 8.3 中使用 Swift 3.1 并看到警告:

Method 'initialize()' defines Objective-C class method 'initialize', which is not guaranteed to be invoked by Swift and will be disallowed in future versions

我使用 Swizzling CocoaTouch class并且对该部分有疑问:

extension UIViewController {

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

    // MARK: - Method Swizzling

    func proj_viewWillAppear(animated: Bool) {
        self.proj_viewWillAppear(animated: animated)

        let viewControllerName = NSStringFromClass(type(of: self))
        print("viewWillAppear: \(viewControllerName)")
    } 
 }

如何重写那部分代码？

open override class func initialize()

修复新警告？

我看到了link ，但我不明白如何在我的代码中使用信息。

Answer 1

我遇到了同样的问题并解决了它。

我的解决方案

1。将 swizzling() 方法从私有(private)更改为公共(public)

public let swizzling: (AnyClass, Selector, Selector) -> () = { forClass, originalSelector, swizzledSelector in
    let originalMethod = class_getInstanceMethod(forClass, originalSelector)
    let swizzledMethod = class_getInstanceMethod(forClass, swizzledSelector)
    method_exchangeImplementations(originalMethod, swizzledMethod)
}

2。移除 extension UIViewController

处的 initialize() 方法

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

3。在 AppDelegate::didFinishLaunchingWithOptions 添加 swizzling()

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    // some code

    swizzling(UIViewController.self)

    return true
}

这是简单/简单的解决方案。 (这不是优雅)

如果你想获得更多信息，请看这里: Swift 3.1 deprecates initialize(). How can I achieve the same thing?