使用动画显示颜色序列(Swift)

import UIKit

class ViewController: UIViewController {
    let colors: [UIColor] = [.red, .green, .blue, .yellow]
    var colorIndex = 0
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建一个UIView作为动画的目标视图
        let targetView = UIView(frame: CGRect(x: 100, y: 100, width: 100, height: 100))
        targetView.backgroundColor = colors[colorIndex]
        view.addSubview(targetView)
        
        // 创建一个定时器，每隔一段时间执行一次动画
        Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { timer in
            UIView.animate(withDuration: 0.5) {
                self.colorIndex = (self.colorIndex + 1) % self.colors.count
                targetView.backgroundColor = self.colors[self.colorIndex]
            }
        }
    }
}