具有自定义单元格高度的垂直UICollectionView居中分页

import UIKit

class ViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
    
    let cellIdentifier = "CustomCell"
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: UICollectionViewFlowLayout())
        collectionView.delegate = self
        collectionView.dataSource = self
        collectionView.register(CustomCell.self, forCellWithReuseIdentifier: cellIdentifier)
        
        view.addSubview(collectionView)
    }
    
    // MARK: - UICollectionViewDataSource
    
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 10 // 假设有10个单元格
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellIdentifier, for: indexPath) as! CustomCell
        
        // 根据indexPath设置单元格内容
        
        return cell
    }
    
    // MARK: - UICollectionViewDelegateFlowLayout
    
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        // 根据indexPath计算每个单元格的高度，并返回CGSize
        let height = // 计算单元格高度的逻辑
        
        return CGSize(width: collectionView.bounds.width, height: height)
    }
    
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
        // 设置每个分页在水平和垂直方向上的间距，使其居中显示
        let horizontalSpacing: CGFloat = 10
        let verticalSpacing: CGFloat = 10
        let insets = UIEdgeInsets(top: verticalSpacing, left: horizontalSpacing, bottom: verticalSpacing, right: horizontalSpacing)
        
        return insets
    }
    
    // MARK: - UICollectionViewDelegate
    
    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        // 处理选中单元格的逻辑
    }
    
}