iOS -在集合视图单元格周围添加边框，并在其下添加视图

import UIKit

class CustomCollectionViewCell: UICollectionViewCell {
    
    let borderView = UIView()
    let bottomView = UIView()
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setupViews()
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setupViews()
    }
    
    private func setupViews() {
        // 设置边框视图
        borderView.backgroundColor = .clear
        borderView.layer.borderWidth = 1.0
        borderView.layer.borderColor = UIColor.black.cgColor
        borderView.layer.cornerRadius = 8.0
        
        // 设置下方视图
        bottomView.backgroundColor = .lightGray
        
        // 添加子视图
        contentView.addSubview(borderView)
        contentView.addSubview(bottomView)
        
        // 使用Auto Layout布局
        borderView.translatesAutoresizingMaskIntoConstraints = false
        bottomView.translatesAutoresizingMaskIntoConstraints = false
        
        NSLayoutConstraint.activate([
            borderView.topAnchor.constraint(equalTo: contentView.topAnchor),
            borderView.leadingAnchor.constraint(equalTo: contentView.leadingAnchor),
            borderView.trailingAnchor.constraint(equalTo: contentView.trailingAnchor),
            borderView.bottomAnchor.constraint(equalTo: bottomView.topAnchor),
            
            bottomView.leadingAnchor.constraint(equalTo: contentView.leadingAnchor),
            bottomView.trailingAnchor.constraint(equalTo: contentView.trailingAnchor),
            bottomView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor),
            bottomView.heightAnchor.constraint(equalToConstant: 5.0)
        ])
    }
}

import UIKit

class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
    
    let collectionView = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        collectionView.dataSource = self
        collectionView.delegate = self
        collectionView.register(CustomCollectionViewCell.self, forCellWithReuseIdentifier: "CustomCell")
        
        view.addSubview(collectionView)
        
        collectionView.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            collectionView.topAnchor.constraint(equalTo: view.topAnchor),
            collectionView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            collectionView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            collectionView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
        ])
    }
    
    // MARK: - UICollectionViewDataSource
    
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 20 // 示例数据
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CustomCell", for: indexPath) as! CustomCollectionViewCell
        return cell
    }
    
    // MARK: - UICollectionViewDelegateFlowLayout
    
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: view.bounds.width, height: 100) // 自定义单元格大小
    }
}