将父容器的平移手势传递给嵌套的UICollectionView

让子视图作为底部视图实际上占据了整个屏幕,并设置集合视图的contentInset。从上到上的视图高度。然后在底部视图上方添加另一个子视图控制器。然后,您需要做的唯一一件事是使父视图控制器成为代理,以侦听底部视图的集合视图的滚动偏移,并更改顶部视图的位置。没有复杂的手势识别器。只有一个滚动视图(集合视图)

更新:试试这个!!

import Foundation
import UIKit

let topViewHeight: CGFloat = 250

class SplitViewController: UIViewController, BottomViewControllerScrollDelegate {

    let topViewController: TopViewController = TopViewController()
    let bottomViewController: BottomViewController = BottomViewController()

    override func viewDidLoad() {
        super.viewDidLoad()

        automaticallyAdjustsScrollViewInsets = false

        bottomViewController.delegate = self
        addViewController(bottomViewController, frame: view.bounds, completion: nil)
        addViewController(topViewController, frame: CGRect(x: 0, y: 0, width: view.frame.size.width, height: topViewHeight), completion: nil)
    }

    func bottomViewScrollViewDidScroll(_ scrollView: UIScrollView) {
        print("\(scrollView.contentOffset.y)")

        let offset = (scrollView.contentOffset.y + topViewHeight)
        if offset < 0 {
            topViewController.view.frame.origin.y = 0
            topViewController.view.frame.size.height = topViewHeight - offset
        } else {
            topViewController.view.frame.origin.y = -(scrollView.contentOffset.y + topViewHeight)
            topViewController.view.frame.size.height = topViewHeight
        }
    }
}

class TopViewController: UIViewController {

    let label = UILabel()

    override func viewDidLoad() {
        super.viewDidLoad()

        automaticallyAdjustsScrollViewInsets = false
        view.backgroundColor = UIColor.red

        label.text = "Top View"
        view.addSubview(label)
    }

    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()
        label.sizeToFit()
        label.center = view.center
    }
}

protocol BottomViewControllerScrollDelegate: class {
    func bottomViewScrollViewDidScroll(_ scrollView: UIScrollView)
}

class BottomViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {

    var collectionView: UICollectionView!

    weak var delegate: BottomViewControllerScrollDelegate?

    let cellPadding: CGFloat = 5

    override func viewDidLoad() {
        super.viewDidLoad()

        view.backgroundColor = UIColor.yellow
        automaticallyAdjustsScrollViewInsets = false

        let layout = UICollectionViewFlowLayout()
        layout.minimumInteritemSpacing = cellPadding
        layout.minimumLineSpacing = cellPadding
        layout.scrollDirection = .vertical
        layout.sectionInset = UIEdgeInsets(top: cellPadding, left: 0, bottom: cellPadding, right: 0)

        collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: layout)
        collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        collectionView.contentInset.top = topViewHeight
        collectionView.scrollIndicatorInsets.top = topViewHeight
        collectionView.alwaysBounceVertical = true
        collectionView.backgroundColor = .clear
        collectionView.dataSource = self
        collectionView.delegate = self
        collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: String(describing: UICollectionViewCell.self))
        view.addSubview(collectionView)
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 30
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: String(describing: UICollectionViewCell.self), for: indexPath)
        cell.backgroundColor = UIColor.darkGray
        return cell
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let width = floor((collectionView.frame.size.width - 2 * cellPadding) / 3)
        return CGSize(width: width, height: width)
    }

    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        delegate?.bottomViewScrollViewDidScroll(scrollView)
    }
}

extension UIViewController {

    func addViewController(_ viewController: UIViewController, frame: CGRect, completion: (()-> Void)?) {
        viewController.willMove(toParentViewController: self)
        viewController.beginAppearanceTransition(true, animated: false)
        addChildViewController(viewController)
        viewController.view.frame = frame
        viewController.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        view.addSubview(viewController.view)
        viewController.didMove(toParentViewController: self)
        viewController.endAppearanceTransition()
        completion?()
    }
}

你不能“放弃”一个手势,因为手势识别器仍然是同一个对象及其 view

然而,没有什么能阻止你告诉其他人对手势的反应。集合视图是一个滚动视图,因此您知道它是如何在每个时刻滚动的,并且可以并行执行其他操作。

UICollectionViewDelegateFlowLayout . 如果您的顶视图需要任何特殊的滚动行为,例如视差,您仍然可以在单个集合视图中通过实现继承自的自定义布局对象来实现这一点 UICollectionViewLayout .

使用 这种方法比实现自定义布局更简单,所以如果您想尝试一下,请尝试以下方法:

• UICollectionViewCell 并在收藏视图中注册。

• func register(_ viewClass: AnyClass?, forSupplementaryViewOfKind elementKind: String, withReuseIdentifier identifier: String)

• 让集合视图控制器符合 UICollectionViewDelegateFlowLayout ,创建布局对象作为的实例 UICollectionViewFlowLayout

• 使生效 optional func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize 在collecton视图控制器中返回每个不同视图的所需大小。