在快速加载视图控制器时执行方法

override func viewDidLoad() {
    super.viewDidLoad()
    // 将耗时操作放到后台线程
    DispatchQueue.global(qos: .userInitiated).async {
        // 执行耗时操作
        DispatchQueue.main.async {
            // 更新UI
        }
    }
}

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    // 避免频繁更新UI，尽量减少在此方法中的操作
}

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    // 使用CADisplayLink或UIView.animate(withDuration:)来优化动画性能
    UIView.animate(withDuration: 0.3, animations: {
        // 动画代码
    })
}

class MyViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        print("viewDidLoad: 加载初始数据")
        // 加载初始数据
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        print("viewWillAppear: 更新界面元素")
        // 更新界面元素
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        print("viewDidAppear: 启动动画")
        // 启动动画
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        print("viewWillDisappear: 清理资源")
        // 清理资源
    }
    
    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)
        print("viewDidDisappear: 完成清理")
        // 完成清理
    }
}