iPhone X系列查看电池故障

Question

我有一个收集视图，其中的单元格是屏幕宽度的1/2。问题是，只有在iPhone X和Xs上，我才有一行显示收藏夹视图下的内容。为什么会这样呢？

import UIKit
import SnapKit

class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate {
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 10
    }

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

    lazy var collectionView: UICollectionView = {
        let layout = UICollectionViewFlowLayout()
        let collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)
        collectionView.delegate = self
        collectionView.dataSource = self
        collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: NSStringFromClass(UICollectionViewCell.self))
        layout.itemSize = CGSize(width: (UIScreen.main.bounds.width / 2), height: UIScreen.main.bounds.width / 2)
        layout.minimumInteritemSpacing = 0
        layout.minimumLineSpacing = 0
        return collectionView
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        view.addSubview(collectionView)

        if #available(iOS 11.0, *) {
            collectionView.contentInsetAdjustmentBehavior = .always
        }

        collectionView.snp.makeConstraints({ make in
            make.edges.equalTo(self.view)
        })
    }



}