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[英]How to pass data from parent view controller to child container view controller
[英]Pass values from container view to parent view controller
我是 swift 的新手,我想將一個數組從我的容器視圖傳遞到父視圖。我已經使用故事板創建了容器視圖,但是容器視圖以編程方式出現和消失,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
我希望每次單擊按鈕以顯示容器視圖時都顯示所選數據。 我不知道如何將值從子視圖控制器傳遞到父視圖控制器,以及我應該在哪里可以訪問這些值。這些值需要在單擊父視圖控制器內的另一個按鈕時調用的函數內部訪問。
這樣做的步驟。
你的容器視圖必須包含一個嵌入到子視圖控制器的 segue,名稱 segue 像這樣......“homeToContainer”(見附件圖片)
將此方法添加到您的父視圖控制器 (DiaryEntryViewController)
override func prepare(for segue: UIStoryboardSegue, sender: Any?) { if let vc = segue.destination as? ChildViewController, segue.identifier == "homeToContainer" { vc.delegate = self } }
在 ChildViewController 中添加協議及其變量:
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() } }
在父 ViewController 的最后一個中,添加此擴展:
extension DiaryEntryViewController:ChildToParentProtocol { func buttonClickedByUser() { } func needToPassInfoToParent(with value:Int) { } }
如果您以編程方式添加容器視圖,則應使用回調將值從容器視圖返回到父視圖。
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)
])
容器視圖控制器
定義這個回調
var callback : ((Bool)->())?
當您將值傳遞給父控制器時,請調用此回調,例如
self.callback?(true) or self.callback?(false)
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