如何以编程方式添加Container View

Question

可以通过界面编辑器轻松地将容器视图添加到故事板中。添加时，Container View具有占位符视图，嵌入segue和（子）视图控制器。

但是，我无法找到以编程方式添加Container View的方法。实际上，我甚至找不到一个名为UIContainerView的类。

Container View类的名称肯定是一个好的开始。我们非常感谢包括segue在内的完整指南。

我知道View Controller Programming Guide，但我不认为它与Interface Builder为Container Viewer的方式相同。例如，正确设置约束后，（子）视图将适应容器视图中的大小更改。

Answer 1

故事板“容器视图”只是标准的UIView对象。没有特殊的“容器视图”类型。实际上，如果查看视图层次结构，可以看到“容器视图”是标准的UIView：

要以编程方式实现此目的，请使用“视图控制器包含”：

• 通过在storyboard对象上调用instantiateViewController(withIdentifier:)来实例化子视图控制器。
• 在父视图控制器中调用addChild。
• 使用view将视图控制器的addSubview添加到视图层次结构中（并根据需要设置frame或约束）。
• 在子视图控制器上调用didMove(toParent:)方法，将引用传递给父视图控制器。

请参阅View Controller编程指南中的Implementing a Container View Controller和UIViewController Class Reference的“实现容器视图控制器”部分。

---

例如，在Swift 4.2中它可能看起来像：

override func viewDidLoad() {
    super.viewDidLoad()

    let controller = storyboard!.instantiateViewController(withIdentifier: "Second")
    addChild(controller)
    controller.view.translatesAutoresizingMaskIntoConstraints = false
    view.addSubview(controller.view)

    NSLayoutConstraint.activate([
        controller.view.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 10),
        controller.view.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -10),
        controller.view.topAnchor.constraint(equalTo: view.topAnchor, constant: 10),
        controller.view.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -10)
    ])

    controller.didMove(toParent: self)
}

注意，上面实际上并没有向层次结构添加“容器视图”。如果你想这样做，你会做类似的事情：

override func viewDidLoad() {
    super.viewDidLoad()

    // add container

    let containerView = UIView()
    containerView.translatesAutoresizingMaskIntoConstraints = false
    view.addSubview(containerView)
    NSLayoutConstraint.activate([
        containerView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 10),
        containerView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -10),
        containerView.topAnchor.constraint(equalTo: view.topAnchor, constant: 10),
        containerView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -10),
    ])

    // add child view controller view to container

    let controller = storyboard!.instantiateViewController(withIdentifier: "Second")
    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)
    ])

    controller.didMove(toParent: self)
}

如果在不同的子视图控制器之间进行转换，并且您只想确保一个子视图位于同一位置和前一个子视图（即，放置的所有唯一约束都由容器视图决定，则后一种模式非常有用，而不是每次都需要重建这些约束。但是如果只是执行简单的视图包含，那么对这个单独的容器视图的需求就不那么引人注目了。

---

在上面的例子中，我将translatesAutosizingMaskIntoConstraints设置为false自己定义约束。你显然可以将translatesAutosizingMaskIntoConstraints留作true并为你添加的视图设置frame和autosizingMask，如果你愿意的话。

---

请参阅Swift 3和Swift 2演绎的此答案的先前修订版。

Answer 2

@ Rob在Swift 3中的回答：

    // add container

    let containerView = UIView()
    containerView.translatesAutoresizingMaskIntoConstraints = false
    view.addSubview(containerView)
    NSLayoutConstraint.activate([
        containerView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 10),
        containerView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -10),
        containerView.topAnchor.constraint(equalTo: view.topAnchor, constant: 10),
        containerView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -10),
        ])

    // add child view controller view to container

    let controller = storyboard!.instantiateViewController(withIdentifier: "Second")
    addChildViewController(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)
        ])

    controller.didMove(toParentViewController: self)

Answer 3

细节

• Xcode 10.2（10E125），Swift 5

解

import UIKit

class WeakObject {
    weak var object: AnyObject?
    init(object: AnyObject) { self.object = object}
}

class EmbedController {

    private weak var rootViewController: UIViewController?
    private var controllers = [WeakObject]()
    init (rootViewController: UIViewController) { self.rootViewController = rootViewController }

    func append(viewController: UIViewController) {
        guard let rootViewController = rootViewController else { return }
        controllers.append(WeakObject(object: viewController))
        rootViewController.addChild(viewController)
        rootViewController.view.addSubview(viewController.view)
    }

    deinit {
        if rootViewController == nil || controllers.isEmpty { return }
        for controller in controllers {
            if let controller = controller.object {
                controller.view.removeFromSuperview()
                controller.removeFromParent()
            }
        }
        controllers.removeAll()
    }
}

用法

class SampleViewController: UIViewController {
    private var embedController: EmbedController?

    override func viewDidLoad() {
        super.viewDidLoad()
        embedController = EmbedController(rootViewController: self)

        let newViewController = ViewControllerWithButton()
        newViewController.view.frame = CGRect(origin: CGPoint(x: 50, y: 150), size: CGSize(width: 200, height: 80))
        newViewController.view.backgroundColor = .lightGray
        embedController?.append(viewController: newViewController)
    }
}

完整样本

视图控制器

import UIKit

class ViewController: UIViewController {

    private var embedController: EmbedController?
    private var button: UIButton?
    private let addEmbedButtonTitle = "Add embed"

    override func viewDidLoad() {
        super.viewDidLoad()

        button = UIButton(frame: CGRect(x: 50, y: 50, width: 150, height: 20))
        button?.setTitle(addEmbedButtonTitle, for: .normal)
        button?.setTitleColor(.black, for: .normal)
        button?.addTarget(self, action: #selector(buttonTapped), for: .touchUpInside)
        view.addSubview(button!)

        print("viewDidLoad")
        printChildViewControllesInfo()
    }

    func addChildViewControllers() {

        var newViewController = ViewControllerWithButton()
        newViewController.view.frame = CGRect(origin: CGPoint(x: 50, y: 150), size: CGSize(width: 200, height: 80))
        newViewController.view.backgroundColor = .lightGray
        embedController?.append(viewController: newViewController)

        newViewController = ViewControllerWithButton()
        newViewController.view.frame = CGRect(origin: CGPoint(x: 50, y: 250), size: CGSize(width: 200, height: 80))
        newViewController.view.backgroundColor = .blue
        embedController?.append(viewController: newViewController)

        print("\nChildViewControllers added")
        printChildViewControllesInfo()
    }

    @objc func buttonTapped() {

        if embedController == nil {
            embedController = EmbedController(rootViewController: self)
            button?.setTitle("Remove embed", for: .normal)
            addChildViewControllers()
        } else {
            embedController = nil
            print("\nChildViewControllers removed")
            printChildViewControllesInfo()
            button?.setTitle(addEmbedButtonTitle, for: .normal)
        }
    }

    func printChildViewControllesInfo() {
        print("view.subviews.count: \(view.subviews.count)")
        print("childViewControllers.count: \(childViewControllers.count)")
    }
}

ViewControllerWithButton

import UIKit

class ViewControllerWithButton:UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    private func addButon() {
        let buttonWidth: CGFloat = 150
        let buttonHeight: CGFloat = 20
        let frame = CGRect(x: (view.frame.width-buttonWidth)/2, y: (view.frame.height-buttonHeight)/2, width: buttonWidth, height: buttonHeight)
        let button = UIButton(frame: frame)
        button.setTitle("Button", for: .normal)
        button.addTarget(self, action: #selector(buttonTapped), for: .touchUpInside)
        view.addSubview(button)
    }

    override func viewWillLayoutSubviews() {
        addButon()
    }

    @objc func buttonTapped() {
        print("Button tapped in \(self)")
    }
}

结果

Answer 4

这是我在swift 3中的代码，也适用于swift 4。

class ViewEmbedder {
    class func embed(
        parent:UIViewController,
        container:UIView,
        child:UIViewController,
        previous:UIViewController?){

        if let previous = previous {
            removeFromParent(vc: previous)
        }
        child.willMove(toParentViewController: parent)
        parent.addChildViewController(child)
        container.addSubview(child.view)
        child.didMove(toParentViewController: parent)
        let w = container.frame.size.width;
        let h = container.frame.size.height;
        child.view.frame = CGRect(x: 0, y: 0, width: w, height: h)
    }

    class func removeFromParent(vc:UIViewController){
        vc.willMove(toParentViewController: nil)
        vc.view.removeFromSuperview()
        vc.removeFromParentViewController()
    }

    class func embed(withIdentifier id:String, parent:UIViewController, container:UIView, completion:((UIViewController)->Void)? = nil){
        let vc = parent.storyboard!.instantiateViewController(withIdentifier: id)
        embed(
            parent: parent,
            container: container,
            child: vc,
            previous: parent.childViewControllers.first
        )
        completion?(vc)
    }
}

用法

@IBOutlet weak var container:UIView!

ViewEmbedder.embed(
    withIdentifier: "MyVC", // Storyboard ID
    parent: self,
    container: self.container){ vc in
    // do things when embed complete
}

将其他嵌入函数与非故事板视图控制器一起使用。