Swift 5-计时器未触发

import UIKit

class ViewController: UIViewController {
    
    var timer: Timer?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 设置一个每隔1秒触发一次的重复计时器
        timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] _ in
            print("计时器触发")
            // 在这里执行你的任务
        }
        
        // 确保计时器在视图控制器销毁时被正确停止
        NotificationCenter.default.addObserver(self, selector: #selector(viewWillDisappear), name: UIApplication.didEnterBackgroundNotification, object: nil)
    }
    
    @objc func viewWillDisappear() {
        timer?.invalidate()
        timer = nil
    }
    
    deinit {
        timer?.invalidate()
        timer = nil
    }
}