【Swift UIKit】UICollectionViewの使い方！グリッドレイアウトの実装方法！

@MainActor  class UICollectionView : UIScrollView

import UIKit

class ViewController: UIViewController,UICollectionViewDelegate,UICollectionViewDataSource {
    // 項目数：UICollectionViewDataSource
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 
    }
    // セル生成：UICollectionViewDataSource
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    }
}

import UIKit

class ViewController: UIViewController,UICollectionViewDelegate,UICollectionViewDataSource {
    
    let numbers: [Int] = Array(0..<60)

    // @IBOutlet  weak var collectionView:UICollectionView!
    
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return numbers.count
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        
        let cell:UICollectionViewCell = collectionView.dequeueReusableCell(withReuseIdentifier: "CollectionCell", for: indexPath)
        let label = cell.contentView.viewWithTag(1) as! UILabel
        
        label.text = String(numbers[indexPath.row])
        return cell
    }
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // コードで紐付けする場合
        // collectionView.delegate = self
        // collectionView.dataSource = self
    }
}

func collectionView(_ collectionView: UICollectionView,   didSelectItemAt indexPath: IndexPath) {
    print(numbers[indexPath.row])
}