UIPageViewController

 1// transitionStyle 指定页面切换时的过渡样式
 2// navigationOrientation 指定页面切换导航方向 水平，垂直
 3let pageVC = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .vertical)
 4
 5// 设置 PageViewController 的 dataSource 和 delegate
 6pageVC.delegate = ...
 7
 8pageVC.dataSource = ...
 9
10// 设置 PageViewController 的 viewControllers
11pageVC.setViewControllers([...], direction: .forward, animated: true, completion: nil)

 1/// 获取页面对应的数据下标索引
 2/// - Parameter entryPage: 页面
 3/// - Returns: 下标索引
 4private func indexOf(ViewController viewController: UIViewController) -> Int? {
 5    // dataSource 中查找 viewController 的索引
 6    // id 字段为 数据 的唯一标识
 7    return dataSource.firstIndex(where: { $0.id == viewController.id })
 8}
 9/// 通过下标索引获取 ViewController
10/// - Parameter index: 下标索引
11/// - Returns: ViewController
12private func viewControllerOf(Index index: Int) -> UIViewController? {
13    let viewControllers = UIViewController()
14    viewController.id = dataSource[index].id
15    return viewController
16}

 1//UIPageViewControllerDataSource  
 2/// 获取上一页的视图控制器
 3func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
 4    // 数据类型转换
 5    guard let vc = viewController as? CustomViewController else { return nil }
 6    // 获取上一页的下标索引
 7    guard let index = indexOf(ViewController: vc) else { return nil }
 8    // 索引校验，防止数据越界
 9    if index <= 0 { return nil}
10    // 返回上一页的视图控制器
11    return viewControllerOf(Index: index - 1)
12}
13
14/// 获取下一页的视图控制器
15func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
16    // 数据类型转换
17    guard let vc = viewController as? CustomViewController else { return nil }
18    // 获取下一页的下标索引
19    guard let index = indexOf(ViewController: vc) else { return nil }
20    // 索引校验，防止数据越界
21    if index >= dataSource.count - 1 { return nil }
22    // 返回下一页的视图控制器
23    return viewControllerOf(Index: index + 1)
24}
25
26func presentationCount(for pageViewController: UIPageViewController) -> Int {
27    //返回 PageControl 中的数量，⚠️⚠️⚠️水平翻页模式下返回1将不会展示页面展示 PageControl
28    return 1
29}
30    
31func presentationIndex(for pageViewController: UIPageViewController) -> Int {
32    //返回在 PageControl 中的选定项的索引
33    return 1
34}

 1/// 下一页
 2public func setupNextPage(){
 3    /// 获取当前展示的视图控制器
 4    guard let currentViewController = pageVC.viewControllers?.first else { return }
 5    /// 获取下一页的视图控制器
 6    guard let nextViewController = pageVC.dataSource?.pageViewController(pageVC, viewControllerAfter: currentViewController) else { return }
 7    /// 设置下一页为当前显示的ViewController
 8    pageVC.delegate?.pageViewController?(pageVC, willTransitionTo: [nextViewController])
 9    pageVC.setViewControllers([nextViewController], direction: .forward, animated: true) { completed in
10        self.pageVC.delegate?.pageViewController?(self.pageVC, didFinishAnimating: true, previousViewControllers: [currentViewController], transitionCompleted: completed)
11}
12
13
14/// 上一页
15public func setupPrevPage(){
16    /// 获取当前展示的视图控制器
17    guard let currentViewController = pageVC.viewControllers?.first else { return }
18    /// 获取上一页的视图控制器
19    guard let prevViewController = pageVC.dataSource?.pageViewController(pageVC, viewControllerBefore: currentViewController) else { return }
20    /// 设置上一页为当前显示的ViewController
21    pageVC.delegate?.pageViewController?(pageVC, willTransitionTo: [prevViewController])
22    pageVC.setViewControllers([prevViewController], direction: .reverse, animated: true) { completed in
23        self.pageVC.delegate?.pageViewController?(self.pageVC, didFinishAnimating: true, previousViewControllers: [currentViewController], transitionCompleted: completed)
24}