Question

如何访问UIPageViewController的最后一项，以便可以将self设置为其委托？

self.present(wizard, animated: true, completion: {
    let lastVC = wizard.viewControllers?.last as! thirdPageController
    lastVC.delegate = self        
})

我认为第三项尚未加载，因此.last返回了错误的页面（第一项）

Answer 1

快速5

创建自己的UIPageViewController：

class MyPageViewController: UIPageViewController {

  private lazy var _viewControllers = [UIViewController]()

  public var lastViewController: UIViewController? {
    return _viewControllers.last
  }

  override func setViewControllers(_ viewControllers: [UIViewController]?, direction: UIPageViewController.NavigationDirection, animated: Bool, completion: ((Bool) -> Void)? = nil) {
    super.setViewControllers([viewController], direction: direction, animated: animated, completion: completion)

    _viewControllers.removeAll()
    _viewControllers.append(viewControllers)
  }

}

课程用法：

let myPageViewController = MyPageViewController()

myPageViewController.lastViewController // This is an optional value

最后，您应该将 wizard UIPageViewController 的类别更改为 MyPageViewController

然后，您可以使用以下新类：

self.present(wizard, animated: true, completion: {

    if let lastViewController = wizard.lastViewController as? thirdPageController {
        lastViewController.delegate = self
    }
})

访问UIPageViewController的最后一个元素

1 个答案: