删除子视图控制器

Question

我有以下代码：

func setUpPageController(viewControllers: [UIViewController]) {
        let pagingViewController = PagingViewController(viewControllers: viewControllers)
        pagingViewController.menuInsets = UIEdgeInsets(top: 1, left: 0, bottom: 1, right: 0)
        pagingViewController.menuItemSize = .selfSizing(estimatedWidth: 100, height: 40)
        pagingViewController.menuBackgroundColor = UIColor.Custom.secondaryColor_white
        pagingViewController.selectedTextColor = UIColor.Custom.secondaryColor_black
        pagingViewController.menuHorizontalAlignment = .center
        pagingViewController.textColor = UIColor.Custom.secondaryColor_black
        
        // Make sure you add the PagingViewController as a child view
        // controller and contrain it to the edges of the view.
        addChild(pagingViewController)
        view.addSubview(pagingViewController.view)
        pagingViewController.view.translatesAutoresizingMaskIntoConstraints = false
        
        NSLayoutConstraint.activate([
            pagingViewController.view.topAnchor.constraint(equalTo: view.topAnchor),
            pagingViewController.view.bottomAnchor.constraint(equalTo: view.bottomAnchor),
            pagingViewController.view.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            pagingViewController.view.trailingAnchor.constraint(equalTo: view.trailingAnchor),
        ])
        
        pagingViewController.didMove(toParent: self)
    }

我想再次调用该函数，但在顶部添加另一个子视图控制器之前删除了子视图控制器。因为第二次有不同的视图控制器，所以应该添加它们或者只是一个不同的数组。

如果我在再次调用该方法时保持原样，则前一个添加的子项显示在滚动边缘的末尾或开始处。

Answer 1

您需要将控制器添加为子控制器，以便稍后将其删除。为此，请使用此代码：

var pagingViewController: PagingViewController?

func removePagingViewController() {
    pagingViewController?.removeFromParent()
    pagingViewController?.view.removeFromSuperview()
}

Answer 2

这是为了使其模块化。

删除单个child:

func removeViewController(_ viewController: UIViewController) {
    // this is to notify the the child that it's about to be removed
    viewController.willMove(toParent: nil)
    // this is to remove the child's view from its superview
    viewController.view.removeFromSuperview()
    // this is to remove the child vc from its parent vc
    viewController.removeFromParent()
}

删除所有children:

func removeAllChildren() {
    if self.children.count > 0 {
        let childrenVC: [UIViewController] = self.children
        for chlidVC in childrenVC {
            chlidVC.willMove(toParent: nil)
            chlidVC.view.removeFromSuperview()
            chlidVC.removeFromParent()
        }
    }
}

删除子视图控制器

Remove child view controller

uipageviewcontroller

childviewcontroller

swift