我想在UIPageView中显示三张图片，但每次刷到第三张图片时，都会出现此错误：'NSRangeException', reason: '*** -[__NSArrayI objectAtIndex:]: index 3 beyond bounds [0 .. 2]'
我已经检查了有关同一问题的其他问题，但无法弄清楚我的问题所处的位置。
以下是输出的其余部分：
*** First throw call stack:
(
0 CoreFoundation 0x000000010a410c65 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x000000010a0a9bb7 objc_exception_throw + 45
2 CoreFoundation 0x000000010a30717e -[__NSArrayI objectAtIndex:] + 190
3 BonBUp 0x0000000109b1a1cb _TFC6BonBUp14ViewController21viewControllerAtIndexfS0_FSiCS_21ContentViewController + 619
4 BonBUp 0x0000000109b1a792 _TFC6BonBUp14ViewController18pageViewControllerfS0_FTCSo20UIPageViewController33viewControllerAfterViewControllerCSo16UIViewController_GSqS2__ + 418
5 BonBUp 0x0000000109b1a84f _TToFC6BonBUp14ViewController18pageViewControllerfS0_FTCSo20UIPageViewController33viewControllerAfterViewControllerCSo16UIViewController_GSqS2__ + 79
6 UIKit 0x000000010afc2c67 -[UIPageViewController _queuingScrollView:viewBefore:view:] + 129
7 UIKit 0x000000010b06044c -[_UIQueuingScrollView _viewAtIndex:loadingIfNecessary:updatingContents:animated:] + 247
8 UIKit 0x000000010b0625c2 -[_UIQueuingScrollView _adjustContentInsets] + 316
9 UIKit 0x000000010b060135 -[_UIQueuingScrollView _replaceViews:updatingContents:adjustContentInsets:animated:] + 763
10 UIKit 0x000000010b063287 -[_UIQueuingScrollView _didScrollWithAnimation:force:] + 1082
11 UIKit 0x000000010b05f42b -[_UIQueuingScrollView layoutSubviews] + 155
12 UIKit 0x000000010aacb9eb -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 536
13 QuartzCore 0x000000010f122ed2 -[CALayer layoutSublayers] + 146
14 QuartzCore 0x000000010f1176e6 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380
15 QuartzCore 0x000000010f117556 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
16 QuartzCore 0x000000010f08386e _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 242
17 QuartzCore 0x000000010f084a22 _ZN2CA11Transaction6commitEv + 462
18 QuartzCore 0x000000010f146085 _ZN2CA7Display11DisplayLink14dispatch_itemsEyyy + 489
19 CoreFoundation 0x000000010a378174 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
20 CoreFoundation 0x000000010a377d35 __CFRunLoopDoTimer + 1045
21 CoreFoundation 0x000000010a339d3d __CFRunLoopRun + 1901
22 CoreFoundation 0x000000010a339366 CFRunLoopRunSpecific + 470
23 GraphicsServices 0x000000010ec4ba3e GSEventRunModal + 161
24 UIKit 0x000000010aa4b8c0 UIApplicationMain + 1282
25 BonBUp 0x0000000109b21327 main + 135
26 libdyld.dylib 0x000000010cfe2145 start + 1
27 ??? 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
以下是 ViewController 中的代码：
import UIKit
class ViewController: UIViewController, UIPageViewControllerDataSource {
var pageViewController: UIPageViewController!
var pageImages: NSArray!
override func viewDidLoad() {
super.viewDidLoad()
self.pageImages = NSArray(objects: "jeans.png", "blusas.png", "leggings.png")
self.pageViewController = self.storyboard?.instantiateViewControllerWithIdentifier("PageViewController") as! UIPageViewController
self.pageViewController.dataSource = self
var startVC = self.viewControllerAtIndex(0) as ContentViewController
var viewControllers = NSArray(object: startVC)
self.pageViewController.setViewControllers(viewControllers as [AnyObject], direction: .Forward, animated: true, completion: nil)
self.pageViewController.view.frame = CGRectMake(0, 30, self.view.frame.width, self.view.frame.size.height - 60)
self.addChildViewController(self.pageViewController)
self.view.addSubview(self.pageViewController.view)
self.pageViewController.didMoveToParentViewController(self)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func viewControllerAtIndex(index: Int) -> ContentViewController
{
var vc: ContentViewController = self.storyboard?.instantiateViewControllerWithIdentifier("ContentViewController") as! ContentViewController
vc.imageFile = self.pageImages[index] as! String
vc.pageIndex = index
return vc
}
// MARK: - Page View Controller Data Source
func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController?
{
var vc = viewController as! ContentViewController
var index = vc.pageIndex as Int
if (index == 0) || (index == NSNotFound)
{
return nil
}
index--
return self.viewControllerAtIndex(index)
}
func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
var vc = viewController as! ContentViewController
var index = vc.pageIndex as Int
if (index == NSNotFound)
{
return nil
}
index++
return self.viewControllerAtIndex(index)
}
func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int
{
return 0
}
}
ContentViewController ：
import UIKit
class ContentViewController: UIViewController {
@IBOutlet weak var imageView: UIImageView!
var pageIndex: Int!
var imageFile: String!
override func viewDidLoad()
{
super.viewDidLoad()
self.imageView.image = UIImage(named: self.imageFile)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
答案 0 :(得分：1)
您不会检查index >= self.pageImages.count是否nil以[{1}}方式返回viewControllerAtIndex，所以当您在最后一页时，它会在viewController之后询问，然后您将结束由于索引超出范围而崩溃，您的方法应如下所示。
func viewControllerAtIndex(index: Int) -> ContentViewController?
{
if index >= self.pageImages.count
{
return nil
}
var vc: ContentViewController = self.storyboard?.instantiateViewControllerWithIdentifier("ContentViewController") as! ContentViewController
vc.imageFile = self.pageImages[index] as! String
vc.pageIndex = index
return vc
}
由于你的方法现在可以返回nil，所以我在方法结束时添加了?，你需要对代码进行一些更改以便现在使用它。