ios - UICollectionView - 当键盘出现时，整个 Collection View 随键盘移动

Question

这不是我想要的效果。仅当 Collection View 设置为水平流布局时才会发生这种情况。我看过其他一些关于这个问题的帖子，但所提供的答案都不起作用。有人找到解决办法了吗？

我提供了两个屏幕截图，显示键盘触发之前和之后的 UITextField。正如您所看到的，UITextField 以及整个 Collection View (看不到)随着键盘一起向上推。通常键盘会被覆盖，对 View 没有影响。

之前

之后

更新提供代码。我用来实现的方法不涉及 Storyboard。

class AppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?


func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.
    window = UIWindow()
    window?.makeKeyAndVisible()

    let layout = UICollectionViewFlowLayout()
    layout.scrollDirection = .horizontal
    let rvc = ViewController(collectionViewLayout: layout)
    window?.rootViewController = rvc

    return true
}

// .... other boilerplate code provided by Apple when you make a new App
}

ViewController.swift

class ViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout, UITextFieldDelegate {
    let homeCellId = "homeCellId"
    let worldCellId = "worldCellId"

    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = UIColor.white
        collectionView?.register(HomeCell.self, forCellWithReuseIdentifier: homeCellId)
        collectionView?.register(WorldCell.self, forCellWithReuseIdentifier: worldCellId)
collectionView?.isPagingEnabled = true
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 2
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: view.frame.width, height: view.frame.height)
    }

    override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        print(indexPath.item)
        let identifier: String
        if indexPath.item == 0 {
            identifier = homeCellId
        } else if indexPath.item == 1 {
            identifier = worldCellId
        }
        else {
            identifier = homeCellId
        }

        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: identifier, for: indexPath)
        cell.backgroundColor = UIColor.blue
        return cell
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
        return 0
    }
}

MyCell.swift

class MyCell: UICollectionViewCell {

    override init(frame: CGRect) {
        super.init(frame: frame)
        self.setupView()
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    func setupView() {

    }


}

HomeCell.swift

class HomeCell: MyCell {
    let weightField: UITextField = UITextField(frame: .zero)
    override func setupView() {
        super.setupView()
        print("HomeCell")
        weightField.backgroundColor = UIColor.white
        weightField.translatesAutoresizingMaskIntoConstraints = false
        weightField.keyboardType = UIKeyboardType.default
        self.addSubview(weightField)

        weightField.topAnchor.constraint(equalTo: self.topAnchor, constant: 200).isActive = true
        weightField.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 50).isActive = true
    }


}

WorldCell.swift

//与 HomeCell 相同

class WorldCell: MyCell {

    override func setupView() {
        super.setupView()
        print("worldcell")
    }


}

Answer 1

好的，我已经找到了解决这个问题的方法。我在 stackoverflow 上关于类似事件的其他几个线程中遇到了这一点，在一种情况下，答案没有投票，并且对该答案留下的评论说它不起作用..

尽管如此，我仍然不清楚为什么其他实现会导致 Collection View 向上移动。尽管窗口、 Root View Controller 及其 subview 以及键盘之间存在一些相关性。我不知道为什么会发生这种情况。

现在开始编写代码并修复..

上述问题中的方法与此处的主要区别在于 Collection View 的初始化方式。我只会发布我更改的内容，因为其余部分都是一样的。

AppDelegate.swift

class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.
        let rvc = ViewController()

        window? = UIWindow()
        window?.makeKeyAndVisible()
        window?.rootViewController = rvc
        return true
    }
}

这里的显着区别是 Root View Controller 不再使用 Collection View Controller 进行初始化。我们使用标准 View Controller 。

ViewController.swift

class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {

    lazy var collView: UICollectionView = {
        let layout = UICollectionViewFlowLayout()
        layout.scrollDirection = .horizontal
        let view = UICollectionView(frame: .zero, collectionViewLayout: layout)
        view.dataSource = self
        view.delegate = self
        return view
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        self.view.backgroundColor = UIColor.darkGray
        collView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cellId")
        collView.register(HomeCell.self, forCellWithReuseIdentifier: "homeCellId")
        self.view.addSubview(collView)
        collView.backgroundColor = UIColor.blue
        collView.translatesAutoresizingMaskIntoConstraints = false
        collView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
        collView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor).isActive = true
        collView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor).isActive = true
        collView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true
        collView.heightAnchor.constraint(equalTo: self.view.heightAnchor, multiplier: 1)
        // Do any additional setup after loading the view, typically from a nib.
    }
}

我们使用 Collection View 作为 subview 初始化 View Controller ，并将我们通常对单元格应用的相同代码