Ios Swift-当用户解除UIReferenceLibraryViewController时运行代码

当用户未命中UIReferenceLibraryViewController时，我需要运行一段代码。但我之前编写的代码在iOS 13上不起作用

以下是我为iOS 12编写的代码：

override func viewDidLoad() {
  if UIReferenceLibraryViewController.dictionaryHasDefinition(forTerm: word) {
    let ref: UIReferenceLibraryViewController = 
      UIReferenceLibraryViewController(term: word)
      ref.reactive
      .trigger(for: #selector(onboardNav.viewDidDisappear(_:)))
      .observe { _ in self.handleModalDismissed() }

      self.present(ref, animated: false, completion: nil)
   }
}

func handleModalDismissed() { // I need to run this function when user presses "Back" button
    self.showAlert(error: false, word: "")
}

---

我刚找到答案！您需要将

UIReferenceLibraryViewController子类化，并覆盖
viewwilldesign
。像这样：

class ReferenceLibraryViewControllerWithDismiss: UIReferenceLibraryViewController {
    override func viewWillDisappear(_ animated: Bool) {
        // your code
    }

}

然后显示
ReferenceLibraryViewControllerWithDisclose
：

let vc = ReferenceLibraryViewControllerWithDismiss()
self.present(vc, animated: true)

快乐编码
 没有属性<代码>反应性-此属性来自某个第三方库吗？我不知道，我在这里读到：是的，你是对的！刚刚意识到它是用在反应可可。。。谢谢