我是 iOS 开发的新手。我一直在学习 Swift，今天，我尝试使用 UICollectionViewController。
我的代码如下：
class ViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
var colView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 20, left: 10, bottom: 10, right: 10)
layout.itemSize = CGSize(width: 90, height: 120)
colView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
colView.dataSource = self
colView.delegate = self
colView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
colView.backgroundColor = UIColor.white
self.view.addSubview(colView)
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> …