ios - Swift 将选择器从另一个 View 触发到一个 View

Question

我有一个底 View 和一个顶 View 。顶 View 具有透明度。当顶 View 被关闭时，我想触发一个 #selector。我无法使用 viewWillAppear 或 viewDidAppear 因为底部 View 仍然可见。如何在底部 View 中触发 #selector？可以替代 viewWillAppear 的东西吗？

主视图后面有一个模糊 View 。我正在使用 self.modalPresentationStyle = .overCurrentContext 来呈现 View 。

Answer 1

Protocol 是最适合您的解决方案。首先你需要像这样创建协议(protocol)

// MARK: - TopViewController Protocol
protocol TopViewControllerDelegate: NSObjectProtocol {
    func topViewWillDismissWith(data: Dictionary<String,String>)
}

在你的 TopViewController 中创建 TopViewControllerDelegate 的属性，当你的 TopViewController 关闭时你需要像 一样调用委托(delegate)方法didTapOnDismissTopView

class TopViewController : UIViewController {
   weak var delegate : TopViewControllerDelegate!
    // so on...

    // MARK: - Action method
       func didTapOnDismissTopView() {
       var dict = [String : String]()
       dict["Amount"] = "$20.00"
       dict["ExpireIn"] = "20day"
       dict["Location"] = "USA"
       dict["message"] = "hello friend this is your Answer"
       self.delegate.topViewWillDismissWith(data: dict) //Must write this line
       self.dismiss(animated: true, completion: nil)
    }
}

现在是时候在 BottomViewController 中实现 TopViewControllerDelegate 协议(protocol)了

class BottomViewController : UIViewController,TopViewControllerDelegate {

    // MARK: - Action method

    func didTapOnDisplayTopView() {
        let topVC = TopViewController()
        topVC.delegate = self
        self.present(topVC, animated: true, completion: nil)
    }
    // MARK: - TopViewControllerDelegate
    // This method will call while topViewControllr Will Dismiss. 
    // if you want to pass data then pass otherwise you can remove perameter from method.
    func topViewWillDismissWith(data: Dictionary<String, String>) {
        // Do here which you want
    }
}

当你呈现 TopViewController 时，你需要分配 delegate 属性。当你的 topViewControllr 将在那时关闭 topViewWillDismissWith 这个方法会被调用。希望对您有所帮助。