wkwebview 中的 UIMenuItem #selector 方法崩溃

Question

UIMenuItem选择器方法在 iOS 11 beta SDK 中崩溃。

-[WKContentViewhighlightText]：无法识别的选择器发送到实例0x7f85df8f3200

方法定义：

func highlightText() 
{
  //
}

UIMenuItem我尝试在WKWebView中添加，

let menuItemHighlight = UIMenuItem.init(title: "Highlight", action: #selector(ContentWebkitView.highlightText))
UIMenuController.shared.menuItems = [menuItemHighlight]

Answer 1

好的，我们终于让它适用于 Swift 4：

1. 在 WKWebView 子类中，添加以下属性和方法：

   // MARK: - Swizzling to avoid responder chain crash    
   var wkContentView: UIView? {
       return self.subviewWithClassName("WKContentView")
   }
   
   
   private func swizzleResponderChainAction() {
       wkContentView?.swizzlePerformAction()
   }
   

2. 然后，向 UIView 添加扩展（我将其放在与 WKWebView 子类相同的文件中，如果您愿意，可以将其设置为 fileprivate）

   // MARK: - Extension used for the swizzling part linked to wkContentView 
   extension UIView {
   
       /// Find a subview corresponding to the className parameter, recursively.
       func subviewWithClassName(_ className: String) -> UIView? {
   
           if NSStringFromClass(type(of: self)) == className {
               return self
           } else {
               for subview in subviews {
                   return subview.subviewWithClassName(className)
               }
           }
           return nil
       }
   
       func swizzlePerformAction() {
           swizzleMethod(#selector(canPerformAction), withSelector: #selector(swizzledCanPerformAction))
       }
   
       private func swizzleMethod(_ currentSelector: Selector, withSelector newSelector: Selector) {
           if let currentMethod = self.instanceMethod(for: currentSelector),
               let newMethod = self.instanceMethod(for:newSelector) {
               let newImplementation = method_getImplementation(newMethod)
               method_setImplementation(currentMethod, newImplementation)
           } else {
               print("Could not find originalSelector")
           }
       }
   
       private func instanceMethod(for selector: Selector) -> Method? {
           let classType = type(of: self)
           return class_getInstanceMethod(classType, selector)
       }
   
       @objc private func swizzledCanPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
           return false
       }
   }
   

现在 UIMenuItem 按预期工作：

但老实说，这真的感觉像是一个黑客攻击，我希望苹果能够解决这个问题:-/

感谢 Stephan Heilner 的回答：/sf/answers/3008980901/