我目前有一个 UIPageController,它可以在滚动时正确检测上一个或下一个 pageIndex
我需要解决的问题是......
示例:- 用户向左或向右滚动,但随后决定在滑动期间取消……因此保留在当前页面上。
pageIndex 更改为待处理页面(下一页),而不是实际的当前页面。
我的代码目前实现了上面的语句:--
func pageViewController(_ pageViewController: UIPageViewController, willTransitionTo pendingViewControllers: [UIViewController]) {
if let itemController = pendingViewControllers[0] as? PageContentViewController {
nextIndex = itemController.pageIndex
print("Page index = \(nextIndex)")
}
}
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
currentIndex = nextIndex
print("Current Page = \(currentIndex)")
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
let itemController = viewController as! PageContentViewController
if itemController.pageIndex < numberOfPages {
return getItemController(itemController.pageIndex+1)
}
return nil
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
let itemController = viewController as! PageContentViewController
if itemController.pageIndex > 0 {
return getItemController(itemController.pageIndex-1)
}
return nil
}
func getItemController(_ itemIndex: Int) -> PageContentViewController? {
if itemIndex < numberOfPages {
let pageItemController = self.storyboard!.instantiateViewController(withIdentifier: "Page1") as! PageContentViewController
pageItemController.pageIndex = itemIndex
return pageItemController
}
return nil
}
我想在页面显示之前获取页码,以便我可以显示特定对象等。
viewControllerAfter 和 viewControllerBefore 似乎并不是每次都被调用,因此我不能依赖这个委托(delegate)方法
最佳答案
我不知道我是如何错过这个的,但在 didFinishAnimating 方法中,它们是一个完成 block
因此以下代码解决了我的问题
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
if completed
{
currentIndex = nextIndex
}
print("Current Page = \(currentIndex)")
}
关于swift - UIPageController - 如果滑动取消则检测当前页面 (SWIFT 3.*),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/40485964/