如何指示用户滑动的方向，而不是下一个和上一个 View Controller ？
我已成功设置 UIPageViewControllerDataSource 委托(delegate)。
这些函数并不指示用户滑动的方向，而是指示下一个和上一个 View Controller 。
func pageViewController(pageViewController: UIPageViewController,
viewControllerBeforeViewController viewController: UIViewController) -> UIViewController?
func pageViewController(_ pageViewController: UIPageViewController,
viewControllerAfterViewController viewController: UIViewController) -> UIViewController?
我试过用这个方法:
func pageViewController(_ pageViewController: UIPageViewController,
didFinishAnimating finished: Bool,
previousViewControllers previousViewControllers: [AnyObject],
transitionCompleted completed: Bool)
随 UIPageViewControllerDelegate 一起提供。 我发现很难将此方法集成到我使用的代码中，如下所示:
import UIKit
class ProView: UIViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate {
var pageViewController: UIPageViewController?
let characterImages = ["character1", "character2"]
override func viewDidLoad() {
super.viewDidLoad()
createPageViewController()
setupPageControl()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func pageViewController(pageViewController: UIPageViewController,
viewControllerAfterViewController ProView: UIViewController) -> UIViewController? {
let itemController = ProView as PageItemController
if itemController.itemIndex+1 < characterImages.count {
return getItemController(itemController.itemIndex+1)
}
return nil
}
func pageViewController(pageViewController: UIPageViewController,
viewControllerBeforeViewController ProView: UIViewController) -> UIViewController? {
let itemController = ProView as PageItemController
if itemController.itemIndex > 0 {
return getItemController(itemController.itemIndex-1)
}
return nil
}
private func getItemController(itemIndex: Int) -> PageItemController? {
if itemIndex < characterImages.count {
let pageItemController = self.storyboard!.instantiateViewControllerWithIdentifier("ItemController") as PageItemController
pageItemController.itemIndex = itemIndex
pageItemController.imageName = characterImages[itemIndex]
return pageItemController
}
return nil
}
func createPageViewController() {
let pageController = self.storyboard!.instantiateViewControllerWithIdentifier("PageController") as UIPageViewController
pageController.dataSource = self
if characterImages.count > 0 {
let firstController = getItemController(0)!
let startingViewControllers: NSArray = [firstController]
pageController.setViewControllers(startingViewControllers, direction: UIPageViewControllerNavigationDirection.Forward, animated: false, completion: nil)
}
pageViewController = pageController
addChildViewController(pageViewController!)
self.view.addSubview(pageViewController!.view)
pageViewController?.didMoveToParentViewController(self)
}
func setupPageControl() {
let appearance = UIPageControl.appearance()
appearance.pageIndicatorTintColor = UIColor.grayColor()
appearance.currentPageIndicatorTintColor = UIColor.whiteColor()
}
func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int {
return characterImages.count
}
func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int {
return 0
}
func pageViewController(pageViewController: UIPageViewController,
didFinishAnimating finished: Bool,
previousViewControllers ProView: [AnyObject],
transitionCompleted completed: Bool) {
if completed {
println("completed!")
} else {
println("not completed")
}
}
}
class PageItemController: UIViewController {
@IBOutlet weak var imageCharacterChoose: UIImageView!
var itemIndex: Int = 0
var imageName: String = "" {
didSet {
if let imageView = imageCharacterChoose {imageCharacterChoose.image = UIImage(named: imageName)
}
}
}
override func viewDidLoad() {
super.viewDidLoad()
imageCharacterChoose!.image = UIImage(named: imageName)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}
我需要获取用户正在浏览的 View Controller 的itemIndex，但我该怎么做呢？我如何正确使用该方法？
谢谢!
最佳答案
关于ios - 如何指示用户滑动的方向，而不是 Swift 中的下一个和上一个 View Controller ？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27926571/