我创建了一个滚动的pageviewcontroller,但我无法显示点/条。根据我的理解,只要导航设置为“水平”并且“过渡”样式设置为“滚动”,但默认情况下应该存在,但不会显示任何内容。
然后我添加了一些额外的代码来添加和设置点,但仍然没有。这是我现在的代码:
import UIKit
class Swipable_Images: UIPageViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate{
var pages = [UIViewController]()
var pageControl = UIPageControl()
override func viewDidLoad() {
super.viewDidLoad()
self.delegate = self
self.dataSource = self
configurePageControl()
let p1: UIViewController! = storyboard?.instantiateViewController(withIdentifier: "stop1_image1")
let p2: UIViewController! = storyboard?.instantiateViewController(withIdentifier: "stop1_image2")
pages.append(p1)
pages.append(p2)
setViewControllers([p1], direction: UIPageViewController.NavigationDirection.forward, animated: false, completion: nil)
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController)->UIViewController?{
let cur = pages.index(of: viewController)!
let prev = abs((cur - 1) % pages.count)
return pages[prev]
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController)->UIViewController?{
let cur = pages.index(of: viewController)!
let nxt = abs((cur+1) % pages.count)
return pages[nxt]
}
func presentationIndex(for pageViewController: UIPageViewController) -> Int {
return pages.count
}
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool){
let pageContentViewController = pageViewController.viewControllers![0]
self.pageControl.currentPage = pages.index(of: pageContentViewController)!
}
//Swipe Indicator Bar
func configurePageControl(){
pageControl = UIPageControl(frame: CGRect(x: self.view.center.x, y: self.view.center.y, width: UIScreen.main.bounds.width, height: 50))
self.pageControl.numberOfPages = pages.count
self.pageControl.currentPage = 0
self.pageControl.tintColor = UIColor.black
self.pageControl.pageIndicatorTintColor = UIColor.white
self.pageControl.currentPageIndicatorTintColor = UIColor.black
self.view.addSubview(pageControl)
}
}
我甚至继续创建了一个新的空白页面视图控制器来测试,根本没有代码。我只是将导航设置为水平和过渡到滚动而没有别的。没有代码或烦恼。我使用用户定义的运行时属性将背景颜色设置为随机蓝色,以便我能够看到导航/点条,如果它在那里,但我仍然一无所获。
我错过了什么?
根据我的理解,只要导航设置为“水平”并且“过渡”样式设置为“滚动”,但默认情况下应该存在,但不会显示任何内容。
你的理解是错误的。
不要添加页面控件。它是内置的。只要你实现这两个方法,它就会显示出来:
func presentationCount(for pvc: UIPageViewController) -> Int {
func presentationIndex(for pvc: UIPageViewController) -> Int {
不幸的是,内置页面控制点是白色的,这使得它们很难看到。使用UIAppearance代理来修复它(通常在applicationDidFinishLaunching
中)。例如:
let proxy = UIPageControl.appearance()
proxy.pageIndicatorTintColor = UIColor.red.withAlphaComponent(0.6)
proxy.currentPageIndicatorTintColor = .red
proxy.backgroundColor = .yellow
至少通过这种方式,您将看到页面控件存在并可以修改细节以适应。
我想你想从presentationCountForPageViewController
实现presentationIndexForPageViewController
和UIPageViewControllerDataSource
试试这个声明:
pageControl = UIPageControl.appearance(whenContainedInInstancesOf: [Swipable_Images.self])
并删除self.view.addSubview(pageControl)