在UIPageViewController - Swift中跟踪页面索引的可靠方法

class YourViewController: UIPageViewController, UIPageViewControllerDelegate {
    // ...
    override func viewDidLoad() {
        super.viewDidLoad()
        self.delegate = self
        // ...
    }
    // ...
}

func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
    if completed, let currentViewController = pageViewController.viewControllers?.first,
        let currentIndex = orderedViewControllers.firstIndex(of: currentViewController) {
        // 当前页面索引为currentIndex
        // 在这里可以进行相应的操作
    }
}

lazy var orderedViewControllers: [UIViewController] = {
    // 设置你的视图控制器数组，按照你的需求进行排序
    // 例如：[viewController1, viewController2, viewController3]
    // ...
}()