我正在编写一个iOS应用程序
UIPageViewController
. 我的根视图控制器是
ViewController
我补充说
uipageview控制器
作为一个孩子的风投。
最初,我
可视控制器
作为页面视图VC委托:
UIPageViewControllerDelegate
:
extension ViewController: UIPageViewControllerDelegate {
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
// set the pageControl.currentPage to the index of the current viewController in pages
if let viewControllers = pageViewController.viewControllers as? [UIViewController] {
if let viewControllerIndex = self.detailPagedVC.pages.index(of: viewControllers[0]) {
self.detailPagedVC.pageControl.currentPage = viewControllerIndex
// if current page is a single person view controller, zoom to that person's face
if let singlePersonViewController = self.detailPagedVC.pages[viewControllerIndex] as? SinglePersonPageViewController {
// print("didFinishAnimating: \(viewControllerIndex)")
self.zoomableImageVC.zoomableImageView.zoom(to: self.identificationResults[viewControllerIndex].face.rect, with: Constants.contentSpanRatio, animated: true)
} else if let summaryPageViewController = self.detailPagedVC.pages[viewControllerIndex] as? SummaryPageViewController {
self.zoomableImageVC.zoomableImageView.zoom(to: self.zoomableImageVC.zoomableImageView.imageView.bounds, with: Constants.contentSpanRatio, animated: true)
} else {
print("gw: err: unkown type of page controller in paged view ")
}
}
}
}
}
这条路很好用。直到我决定将授权职能转移到一个专门的班级:
class PeoplePageViewDelegate: NSObject, UIPageViewControllerDelegate{
private struct Constants {
// the ratio of the content (e..g face) taken inside the entire view
static let contentSpanRatio: CGFloat = 0.8
}
// store a reference to the object which will take the actual action
// action 1: zooming
weak var zoomingActionTaker: ZoomableImageView?
// action 2: paging
weak var pagingActionTaker: PeoplePageViewController?
// the delegator who relies on this object
unowned let delegator: PeoplePageViewController
init(delegator: PeoplePageViewController) {
self.delegator = delegator
// wire back to delegator
// self.pagingActionTaker = delegator // gw: mind the nuance difference, you chain a weak ref on a unowned ref, what can go wrong?
super.init()
}
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
print("gw:0")
// set the pageControl.currentPage to the index of the current viewController in pages
if let viewControllers = pageViewController.viewControllers as? [UIViewController] {
print("gw:1")
if let viewControllerIndex = self.delegator.pages.index(of: viewControllers[0]) {
print("gw:2")
self.pagingActionTaker?.pageControl.currentPage = viewControllerIndex
// if current page is a single person view controller, zoom to that person's face
if let singlePersonViewController = self.delegator.pages[viewControllerIndex] as? SinglePersonPageViewController {
print("gw:3")
self.zoomingActionTaker?.zoom(to: singlePersonViewController.identification.face.rect, with: Constants.contentSpanRatio, animated: true)
} else if let summaryPageViewController = self.delegator.pages[viewControllerIndex] as? SummaryPageViewController,
let entireImageBounds = self.zoomingActionTaker?.imageView.bounds {
print("gw:4")
self.zoomingActionTaker?.zoom(to: entireImageBounds, with: Constants.contentSpanRatio, animated: true)
} else {
print("gw: err: unkown type of page controller in paged view ")
}
}
}
}
}
这导致了问题:功能
pageViewController(_: didFinishAnimating:previousViewControllers:transitionCompleted)
完全不调用,尽管我已将委托设置为此新类的实例。
我唯一能想到的是,新的委托对象不再是一个VC(它曾经是我的主VC)。所以我怀疑这种行为的改变与风投的等级制度有关?
我错过什么了吗?
