我正在使用
Xcode 6 GM.我正在尝试实现这个
page view controller tutorial但是在Swift中而不是Objective-C但它没有按预期工作.
@H_301_2@我实际上设法找到了其他人正在做同样的git repo,但是在克隆他们的项目并在Xcode中打开它之后,我遇到了同样的错误.在实现UIPageViewControllerDataSource协议时,除了协议一致性问题之外,我已经设法解决了大部分问题.
@H_301_2@说实话,我不完全明白其用法？而且！在斯威夫特,如果这是导致我的问题.删除！从协议的方法实现中的变量引起其他错误.
@H_301_2@有人可以帮忙吗？
class ViewController: UIViewController,UIPageViewControllerDataSource {
var pageViewController : UIPageViewController?
var pageTitles = ["Over 200 Tips and Tricks","Discover Hidden Features","Bookmark Favorite Tip","FreeRegular Update"]
var pageImages = ["page1.png","page2.png","page3.png","page4.png"]
var currentIndex = 0
@IBAction func startWalkthrough(sender: UIButton) {
var startingViewController : PageContentViewController = self.viewControllerAtIndex(0)!
var viewControllers : NSArray = [startingViewController]
self.pageViewController!.setViewControllers(viewControllers,direction: .Forward,animated: false,completion: nil)
}
override func viewDidLoad() {
super.viewDidLoad()
//Create page view controller
self.pageViewController = UIPageViewController(transitionStyle: .Scroll,navigationOrientation: .Horizontal,options: nil)
self.pageViewController!.dataSource = self
let startingViewController : PageContentViewController = self.viewControllerAtIndex(0)!
let viewControllers: NSArray = [startingViewController]
self.pageViewController!.setViewControllers(viewControllers,completion: nil)
// Change the size of page view controller
self.pageViewController!.view.frame = CGRectMake(0,self.view.frame.size.width,self.view.frame.size.height - 30);
self.addChildViewController(self.pageViewController!)
self.view.addSubview(self.pageViewController!.view)
self.pageViewController!.didMoveToParentViewController(self)
}
func pageViewController(pageViewController: UIPageViewController!,viewControllerBeforeViewController viewController: UIViewController!) -> UIViewController! {
var index = (viewController as PageContentViewController).pageIndex
if index == 0 || index == NSNotFound {
return nil
}
index!--
println("Decreasing Index: \(index)")
return self.viewControllerAtIndex(index!)
}
func pageViewController(pageViewController: UIPageViewController!,viewControllerAfterViewController viewController: UIViewController!) -> UIViewController! {
var index = (viewController as PageContentViewController).pageIndex
if index == NSNotFound {
return nil
}
index!++
println("Increasing Index: \(index)")
if index == self.pageTitles.count {
return nil;
}
return self.viewControllerAtIndex(index!);
}
func viewControllerAtIndex(index : Int) -> PageContentViewController? {
if self.pageTitles.count == 0 || index >= self.pageTitles.count {
return nil;
}
// Create a new view controller and pass suitable data.
let pageContentViewController = self.storyboard!.instantiateViewControllerWithIdentifier("PageContentViewController") as PageContentViewController
pageContentViewController.imageFile = self.pageImages[index]
pageContentViewController.titleText = self.pageTitles[index]
pageContentViewController.pageIndex = index
return pageContentViewController;
}
func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int {
return self.pageTitles.count
}
func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int {
return 0
}
}
解决方法
这是因为UIPageViewControllerDataSource协议具有更新的方法签名 – 您正在使用：
func pageViewController(pageViewController: UIPageViewController!,viewControllerBeforeViewController viewController: UIViewController!) -> UIViewController! func pageViewController(pageViewController: UIPageViewController!,viewControllerAfterViewController viewController: UIViewController!) -> UIViewController!@H_301_2@但现在它们是：
func pageViewController(pageViewController: UIPageViewController,viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? func pageViewController(pageViewController: UIPageViewController,viewControllerAfterViewController viewController: UIViewController) -> UIViewController?@H_301_2@当您对不符合协议有疑问时,命令单击协议名称将带您进入协议声明,您可以在其中查看是否正确实现其接口
