我有一个UIViewController,我通过编程方式添加了UIPageViewController。如果我们处于0索引或最后一个索引,如何停止反弹(滚动)UIViewController?我的意思是反弹。
您可以查看以下链接:How to create PageView with UITabBar or Segment Control using swift?
这是我的代码:
import UIKit
class ViewController: UIViewController {
fileprivate var pageViewController:UIPageViewController!
@IBOutlet weak var paginationView:UIView!
@IBOutlet var btnYourGroup: UIButton!
@IBOutlet var btnSharedBy: UIButton!
@IBOutlet var sliderViewLeadingConst: NSLayoutConstraint!
fileprivate var selectedIndex : Int? {
didSet {
var leading:CGFloat = 0
if selectedIndex == 0 {
leading = 0
}
else {
leading = self.view.frame.size.width/2
}
self.sliderViewLeadingConst.constant = leading
UIView.animate(withDuration: 0.2, animations: {
self.view.layoutIfNeeded()
})
}
}
override func viewDidLoad() {
super.viewDidLoad()
//SetUp Pagination
setupPagination()
for view in self.pageViewController.view.subviews {
if let scrollView = view as? UIScrollView {
scrollView.delegate = self
break
}
}
//btnSharedBy.titleColor(for: UIControlState)
btnSharedBy.setTitleColor(UIColor.lightGray, for: UIControlState())
}
private func setupPagination() {
let startVC = self.viewControllerAtIndex(index: 0)
let vc = [startVC]
self.pageViewController = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: nil)
self.pageViewController.setViewControllers(vc, direction: .reverse, animated: true, completion: nil)
self.pageViewController.dataSource = self
self.pageViewController.delegate = self
self.pageViewController.view.frame.size = self.paginationView.frame.size
self.paginationView.addSubview(self.pageViewController.view)
}
@IBAction func mainCateogryTapped(sender:UIButton) {
loadNextController(index:sender.tag)
}
fileprivate func viewControllerAtIndex(index:Int) -> PageContentViewController {
let feedsVC = self.storyboard?.instantiateViewController(withIdentifier: "PageContentViewController") as! PageContentViewController
feedsVC.pageIndex = index
return feedsVC
}
fileprivate func loadNextController(index:Int) {
if selectedIndex == index {
return
}
let nextViewController = viewControllerAtIndex(index:index)
selectedIndex = index
if index == 0 {
btnSharedBy.setTitleColor(UIColor.lightGray, for: UIControlState())
btnYourGroup.setTitleColor(UIColor.white, for: UIControlState())
self.pageViewController?.setViewControllers([nextViewController], direction: UIPageViewControllerNavigationDirection.reverse, animated: true, completion: nil)
} else if index == 1 {
btnSharedBy.setTitleColor(UIColor.white, for: UIControlState())
btnYourGroup.setTitleColor(UIColor.lightGray, for: UIControlState())
self.pageViewController?.setViewControllers([nextViewController], direction: UIPageViewControllerNavigationDirection.forward, animated: true, completion: nil)
}
else {
}
}
}
extension ViewController: UIPageViewControllerDataSource {
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
var index = (viewController as! PageContentViewController).pageIndex
if index == 0 {
return nil
}
index = index - 1
return viewControllerAtIndex(index:index)
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
var index = (viewController as! PageContentViewController).pageIndex
index = index + 1
if index == 2 {
//self.pageViewController.
return nil
}
return viewControllerAtIndex(index:index)
}
func pageViewController(_ pageViewController: UIPageViewController, willTransitionTo pendingViewControllers: [UIViewController]) {
let vc : PageContentViewController = pendingViewControllers[0] as! PageContentViewController
selectedIndex = vc.pageIndex
}
}
extension ViewController : UIPageViewControllerDelegate {
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
if completed {
let vc = previousViewControllers.first as! PageContentViewController
if 0 == vc.pageIndex {
selectedIndex = 1
btnSharedBy.setTitleColor(UIColor.white, for: UIControlState())
btnYourGroup.setTitleColor(UIColor.lightGray, for: UIControlState())
}
else {
btnYourGroup.setTitleColor(UIColor.white, for: UIControlState())
btnSharedBy.setTitleColor(UIColor.lightGray, for: UIControlState())
selectedIndex = 0
}
}
else if !completed {
let pageContentView = previousViewControllers[0] as! PageContentViewController;
self.selectedIndex = pageContentView.pageIndex
}
}
}
//ScrollView Delegate
extension ViewController : UIScrollViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let point = scrollView.contentOffset
var percentComplete: CGFloat
percentComplete = fabs(point.x - view.frame.size.width)/view.frame.size.width
//NSLog("percentComplete: %f", percentComplete)
if(0.8 > percentComplete)
{
//selectedIndex = 1
scrollView.bounces = false
}
else
{
scrollView.bounces = true
}
}
}
如何使用按钮指示器在第一个和最后一个索引处停止弹跳问题?
答案 0 :(得分:2)
您可以浏览页面视图控制器的子视图,查找它的滚动视图,并将跳出设置为false。然而,这是一个脆弱的解决方案,并且不明智。 (弄乱视图控制器的视图通常是一个坏主意,特别是如果没有公共界面可以找到它们。)
下面的线程有代码,用于遍历页面视图控制器的子视图并查找滚动视图。可以很容易地调整该代码以将bounces
属性设置为false: