UIPageViewController中的断言失败
UIPageViewController中的断言失败
提问于 2017-03-16 20:12:51
我在UIPageViewController中有一个断言失败。
Assertion failure in -[UIPageViewController _flushViewController:animated:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKit/UIKit-3512.60.12/UIPageViewController.m
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason:
'Don't know about flushed view <UIView: 0x15a5bff30; frame = (0 0; 768 903); autoresize = W+H; layer = <CALayer: 0x15a5bfc30>>'
*** First throw call stack:
(0x181ebedb0 0x181523f80 0x181ebec80 0x182844154 0x1877a1c40 0x1877a1da8 0x18784e9c4 0x18784ebfc 0x187852318 0x18784dd98 0x1870101e4 0x1849a2994 0x18499d5d0 0x1870270a4 0x10028b620 0x100348b78 0x100379f54 0x100168878 0x18733d568 0x1870330b4 0x1870f1a00 0x18733e71c 0x1870f832c 0x18703536c 0x18700f7ac 0x18700ed40 0x18700eba8 0x1873283b4 0x18700d5e8 0x18784ebd4 0x187852318 0x18784df3c 0x1871db550 0x1871daf6c 0x101c9b768 0x1849f0234 0x1849f00e8 0x182135e54 0x181e5d030 0x181e757d4 0x181e74f0c 0x181e72c64 0x181d9cc50 0x183684088 0x18707e088 0x10033b200 0x18193a8b8)
libc++abi.dylib: terminating with uncaught exception of type NSException我不知道为什么会发生这个错误。有什么原因或者如何调试它的线索吗？
回答 6
Stack Overflow用户
发布于 2018-02-02 09:44:03
遇到这个断言的直接方法是使用使用滚动转换样式定义的UIPageController的循环源。
当源代码包含两个页面时，每个页面都是前一页，下一页是另一页。如果您滑动包含两个页面的UIPageController，然后尝试将源设置为3个页面，您将得到上面提到的断言，并保证假设UIPageControllerDataSource之前/之后的方法在2个页面的情况下允许循环转换。
将UIPageController与滚动过渡配合使用时，避免崩溃的主要规则如下：
1)调用setViewControllers方法前设置dataSource
2)使用不带动画的setViewControllers方法(animated: false)
3)将单页模式的dataSource设置为空
4) 2页模式不允许循环
所有这些建议结合在一起，使UIPageController绝对稳定。
import UIKit
/// Convenient subclass of UIPageViewController
@objc class AMPageViewController: UIPageViewController {
/// Turn on/off PageControl at the bottom
@objc var showPageControl: Bool = true
/// Array of all viewControllers
@objc var source: [UIViewController]? {
didSet {
let count = source?.count ?? 0
if count > 0 {
dataSource = count > 1 ? self : nil
}
else {
dataSource = nil
delegate = nil
}
}
}
/// Index of the current viewController from source
@objc var pageIndex: Int {
get {
var currentPageIndex: Int = 0
if let vc = viewControllers?.first, let source = source, let pageIndex = source.index(of: vc) {
currentPageIndex = pageIndex
}
return currentPageIndex
}
set {
guard newValue >= 0, let source = source, newValue < source.count else { return }
let vc = source[newValue]
let direction: UIPageViewControllerNavigationDirection = newValue < pageIndex ? .reverse : .forward
setViewController(vc, direction: direction)
}
}
override weak var delegate: UIPageViewControllerDelegate? {
get { return super.delegate }
set {
if source?.count ?? 0 > 0 {
super.delegate = newValue
}
else {
super.delegate = nil
}
}
}
/// Initializer in scroll-mode with interPageSpacing
@objc init(navigationOrientation: UIPageViewControllerNavigationOrientation = .horizontal, interPageSpacing: Int = 0) {
let options = (interPageSpacing > 0) ? [UIPageViewControllerOptionInterPageSpacingKey : 5] : nil
super.init(transitionStyle: .scroll, navigationOrientation: navigationOrientation, options: options)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
/// Set viewcontroller by index from source
@objc func setPageIndex(_ index: Int, completion: ((Bool) -> Void)? = nil) {
guard index > 0, let source = source, index < source.count else { return }
let vc = source[index]
let direction: UIPageViewControllerNavigationDirection = index < pageIndex ? .reverse : .forward
setViewController(vc, direction: direction, completion: completion)
}
private func setViewController(_ viewController: UIViewController, direction: UIPageViewControllerNavigationDirection = .forward, completion: ((Bool) -> Void)? = nil) {
super.setViewControllers([viewController], direction: direction, animated: false, completion: completion)
}
}
extension FFPageViewController: UIPageViewControllerDataSource {
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
guard let source = source, let index = source.index(of: viewController) else { return nil }
let count = source.count
if count == 2, index == 0 {
return nil
}
let prevIndex = (index - 1) < 0 ? count - 1 : index - 1
let pageContentViewController: UIViewController = source[prevIndex]
return pageContentViewController
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
guard let source = source, let index = source.index(of: viewController) else { return nil }
let count = source.count
if count == 2, index == 1 {
return nil
}
let nextIndex = (index + 1) >= count ? 0 : index + 1
let pageContentViewController = source[nextIndex]
return pageContentViewController
}
func presentationCount(for pageViewController: UIPageViewController) -> Int {
return showPageControl ? (source?.count ?? 0) : 0
}
func presentationIndex(for pageViewController: UIPageViewController) -> Int {
guard showPageControl else { return 0 }
return pageIndex
}
}可以在GitHub project找到的整体实现和使用示例。
Stack Overflow用户
发布于 2019-01-03 12:05:24
当UIPageViewController转换时，其内部的ViewController (例如: UITableViewController)转换将导致崩溃。
在我的例子中(crash)：
step1
self.pageViewController.setViewControllers([self.tableViewController2], direction: .forward, animated: true, completion: nil)step2
滚动tableView while UIPageViewController过渡。
My Solution
(禁用目标视图控制器和当前视图控制器的滚动)
self.tableViewController1.tableView.isScrollEnabled = false
self.tableViewController2.tableView.isScrollEnabled = false
self.pageViewController.setViewControllers([self.tableViewController2], direction: .forward, animated: true, completion: { _ in
self.tableViewController1.tableView.isScrollEnabled = true
self.tableViewController2.tableView.isScrollEnabled = true
})Stack Overflow用户
发布于 2017-05-05 16:00:18
当我在子控制器中有文本字段，并且没有关闭滚动到下一个控制器的键盘时，这也发生在我身上。如果是这种情况，只需添加endEditing，您可以在其中以编程方式更改控制器，或者滚动到pageViewController scrollViewDidScroll委托方法
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/42833765
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