将值从容器视图传递到父视图控制器

Pass values from container view to parent view controller

我是 swift 的新手,我想将一个数组从我的容器视图传递给父级 view.I 已经使用故事板创建了容器视图,但是容器视图以编程方式出现和消失,如图所示以下:

//in parent view controller, inside viewDidLoad()
CameraView.isHidden  = true

//in child view controller, on click of button,
let parent = self.parent as! DiaryEntryViewController
parent.CameraView.isHidden  = true

我希望在单击按钮显示容器视图时显示所选数据。 我不知道如何将值从子视图控制器传递到父视图控制器,我应该在哪里可以访问函数内需要访问的 values.These 值,该函数在单击父视图内的另一个按钮时调用控制器。

执行此操作的步骤。

  1. 你的容器视图必须包含一个嵌入到子视图控制器的转场,将转场命名为这样的东西......"homeToContainer"(见附图)

  2. 将此方法添加到您的父视图控制器 (DiaryEntryViewController )

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
            if let vc = segue.destination as? ChildViewController,
                segue.identifier == "homeToContainer" {
                vc.delegate = self
            }
    }
    
  3. 在子节点中添加协议及其变量ViewController:

        protocol ChildToParentProtocol:class {
    
    
            func buttonClickedByUser()
            func needToPassInfoToParent(with value:Int)
    
        }
    
    
        class ChildViewController: UIViewController {
    
            weak var delegate:ChildToParentProtocol? = nil
    
            @IBAction func createTourPressed(_ sender: UIButton) {
                // Call here delegate methods to tell parent about the action
                delegate?.buttonClickedByUser()
    
            }
    
        }
    
  4. 在你父 ViewController 的最后,添加这个扩展:

            extension DiaryEntryViewController:ChildToParentProtocol {
    
                func buttonClickedByUser() {
    
                }
                func needToPassInfoToParent(with value:Int) {
    
    
                }
            }
    

如果您以编程方式添加容器视图,则应使用回调将值从容器视图返回到父视图。

父控制器:

let containerView = UIView()
containerView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(containerView)

NSLayoutConstraint.activate([
    containerView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 0),
    containerView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: 0),
    containerView.topAnchor.constraint(equalTo: headerView.bottomAnchor, constant: 0),
    containerView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0),
    ])

let controller = YourViewController(nibName: "YourNibView", bundle: nil)

//This is important to get value back and also define callback to container view call as well
controller.callback = { result in
    self.isCardJoinedFromJoinScreen = true
    self.viewWillAppear(true)
}
addChild(controller)
controller.view.translatesAutoresizingMaskIntoConstraints = false
containerView.addSubview(controller.view)

NSLayoutConstraint.activate([
    controller.view.leadingAnchor.constraint(equalTo: containerView.leadingAnchor),
    controller.view.trailingAnchor.constraint(equalTo: containerView.trailingAnchor),
    controller.view.topAnchor.constraint(equalTo: containerView.topAnchor),
    controller.view.bottomAnchor.constraint(equalTo: containerView.bottomAnchor)
    ])

容器视图控制器
定义这个回调

var callback : ((Bool)->())?

并且在您将值传递给父控制器时调用此回调,如

self.callback?(true) or self.callback?(false)