我正在尝试使用for循环填充一个名为数字的数组，数字为1 - 10。然而，由于某些原因，我不知道，一切都崩溃了。
这是我尝试过的：
for (int counter = 0; counter < 10; counter++) {
if (!numbers)
{
self.numbers = [[NSMutableArray alloc]init];
}
[numbers addObject: [NSNumber numberWithInt:counter]];
}
NSLog(@"%lu", [numbers count]);
并将数字放入表格单元格中：
cell.textLabel.text = [numbers objectAtIndex:indexPath.row];
我不知道为什么一切都崩溃了，我正在做的事似乎对我来说。
我收到了这个错误：
2013-12-13 20:52:29.788 TopNumbers[4003:70b] 10
2013-12-13 20:52:29.792 TopNumbers[4003:70b] -[__NSCFNumber length]: unrecognized selector sent to instance 0xb000000000000002
2013-12-13 20:52:29.796 TopNumbers[4003:70b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFNumber length]: unrecognized selector sent to instance 0xb000000000000002'
*** First throw call stack:
(
0 CoreFoundation 0x000000010188e795 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x00000001015f1991 objc_exception_throw + 43
2 CoreFoundation 0x000000010191fbad -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
3 CoreFoundation 0x000000010188009d ___forwarding___ + 973
4 CoreFoundation 0x000000010187fc48 _CF_forwarding_prep_0 + 120
5 Foundation 0x00000001011e89cb -[NSConcreteMutableAttributedString replaceCharactersInRange:withString:] + 46
6 Foundation 0x00000001011e94a6 -[NSConcreteMutableAttributedString initWithString:attributes:] + 249
7 UIKit 0x00000001003c7497 -[UILabel _setText:] + 85
8 TopNumbers 0x0000000100001b40 -[XYZViewController tableView:cellForRowAtIndexPath:] + 352
9 UIKit 0x000000010031fb8a -[UITableView _createPreparedCellForGlobalRow:withIndexPath:] + 348
10 UIKit 0x0000000100307836 -[UITableView _updateVisibleCellsNow:] + 2297
11 UIKit 0x0000000100318381 -[UITableView layoutSubviews] + 207
12 UIKit 0x00000001002afb27 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 354
13 QuartzCore 0x0000000103df5a22 -[CALayer layoutSublayers] + 151
14 QuartzCore 0x0000000103dea589 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 363
15 UIKit 0x00000001002a4470 -[UIView(Hierarchy) layoutBelowIfNeeded] + 521
16 UIKit 0x0000000100360a96 -[UINavigationController _layoutViewController:] + 1077
17 UIKit 0x000000010035e374 -[UINavigationController navigationTransitionView:didEndTransition:fromView:toView:] + 395
18 UIKit 0x000000010029534e -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 235
19 UIKit 0x0000000100293e44 +[UIViewAnimationState popAnimationState] + 281
20 UIKit 0x000000010051355e -[UINavigationTransitionView transition:fromView:toView:] + 2504
21 UIKit 0x0000000100512b94 -[UINavigationTransitionView transition:toView:] + 25
22 UIKit 0x0000000100361797 -[UINavigationController _startTransition:fromViewController:toViewController:] + 2893
23 UIKit 0x0000000100361a47 -[UINavigationController _startDeferredTransitionIfNeeded:] + 547
24 UIKit 0x00000001003624f8 -[UINavigationController __viewWillLayoutSubviews] + 43
25 UIKit 0x00000001004767e1 -[UILayoutContainerView layoutSubviews] + 202
26 UIKit 0x00000001002afb27 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 354
27 QuartzCore 0x0000000103df5a22 -[CALayer layoutSublayers] + 151
28 QuartzCore 0x0000000103dea589 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 363
29 QuartzCore 0x0000000103df5956 -[CALayer layoutIfNeeded] + 162
30 UIKit 0x000000010034ffc2 -[UIViewController window:setupWithInterfaceOrientation:] + 264
31 UIKit 0x000000010028eb4d -[UIWindow _setRotatableClient:toOrientation:updateStatusBar:duration:force:isRotating:] + 4360
32 UIKit 0x000000010028da3f -[UIWindow _setRotatableClient:toOrientation:updateStatusBar:duration:force:] + 36
33 UIKit 0x000000010028d98f -[UIWindow _setRotatableViewOrientation:updateStatusBar:duration:force:] + 101
34 UIKit 0x000000010028cc9e -[UIWindow _updateToInterfaceOrientation:duration:force:] + 377
35 UIKit 0x0000000100343d4a -[UIViewController _tryBecomeRootViewControllerInWindow:] + 147
36 UIKit 0x0000000100287a87 -[UIWindow addRootViewControllerViewIfPossible] + 506
37 UIKit 0x0000000100287bd5 -[UIWindow _setHidden:forced:] + 275
38 UIKit 0x0000000100290ca2 -[UIWindow makeKeyAndVisible] + 51
39 UIKit 0x000000010024f0c8 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1449
40 UIKit 0x0000000100252be8 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 660
41 UIKit 0x0000000100263aab -[UIApplication handleEvent:withNewEvent:] + 3092
42 UIKit 0x0000000100263f1e -[UIApplication sendEvent:] + 79
43 UIKit 0x00000001002542be _UIApplicationHandleEvent + 618
44 GraphicsServices 0x0000000103996bb6 _PurpleEventCallback + 762
45 GraphicsServices 0x000000010399667d PurpleEventCallback + 35
46 CoreFoundation 0x0000000101810819 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 41
47 CoreFoundation 0x00000001018105ee __CFRunLoopDoSource1 + 478
48 CoreFoundation 0x0000000101839ab3 __CFRunLoopRun + 1939
49 CoreFoundation 0x0000000101838f33 CFRunLoopRunSpecific + 467
50 UIKit 0x00000001002524bd -[UIApplication _run] + 609
51 UIKit 0x0000000100254043 UIApplicationMain + 1010
52 TopNumbers 0x0000000100001fd3 main + 115
53 libdyld.dylib 0x0000000101f1d5fd start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
答案 0 :(得分：1)
UILabel的text属性想要一个字符串，但是你给它一个NSNumber。您想获取数字的字符串值。
答案 1 :(得分：1)
使用此：
cell.textLabel.text = [NSString stringWithFormat:@"%@", [numbers objectAtIndex:indexPath.row]] ;
并且你也说“如果我注释掉[数字addObject：[NSNumber numberWithInt：counter]] ;,它不会崩溃......” 因为如果你注释掉，数字的数量是零，所以从不需要单元格。
答案 2 :(得分：0)
您应该使用：
cell.textLabel.text = [[numbers objectAtIndex:indexPath.row] stringValue];