Question

我是swift的新手，我希望将数组从容器视图传递到父视图。我使用故事板创建了容器视图，但容器视图以编程方式显示和消失，如下所示：

//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

每当我点击按钮显示容器视图时，我希望显示所选数据。我不知道如何将值从子视图控制器传递到父视图控制器，我在哪里可以访问这些值。这些值需要在一个函数内访问，该函数在单击父视图控制器内的另一个按钮时调用。

Answer 1

这样做的步骤。

你的容器视图必须包含一个嵌入到子视图控制器的segue，这个名称就像这样...... ...＃34; homeToContainer＆＃34; （见附图）

将此方法添加到父视图控制器（DiaryEntryViewController）

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if let vc = segue.destination as? ChildViewController,
            segue.identifier == "homeToContainer" {
            vc.delegate = self
        }
}

在ChildViewController中添加Protocol及其变量

    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()

        }

    }

在您的父ViewController的最后一个中，添加此扩展，扩展DiaryEntryViewController：ChildToParentProtocol {

            func buttonClickedByUser() {

            }
            func needToPassInfoToParent(with value:Int) {


            }
        }

Answer 2

如果以编程方式添加了容器视图，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
定义此回调

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

，然后在将值传递给父控制器时调用此回调，如

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

将值从容器视图传递到父视图控制器

2 个答案: