在main函数中收到此错误消息。我是Xcode 5中调试此类错误的新手，所以非常感谢您就如何处理此类错误提出建议。
提前致谢。
以下是代码：
主：
#import <UIKit/UIKit.h>
#import "BullsEyeAppDelegate.h"
int main(int argc, char * argv[])
{
@autoreleasepool {
return UIApplicationMain(argc, argv, nil, NSStringFromClass([BullsEyeAppDelegate class])); //Thread 1: signal SIGABRT
}
}
BullsEyeViewController.h
#import <UIKit/UIKit.h>
@interface BullsEyeViewController : UIViewController
@property (nonatomic, weak) IBOutlet UISlider *slider;
@property (nonatomic, weak) IBOutlet UILabel *targetLabel;
@property (nonatomic, weak) IBOutlet UILabel *scoreLabel;
@property (nonatomic, weak) IBOutlet UILabel *roundLabel;
-(IBAction)showAlert;
-(IBAction)sliderMoved:(UISlider *)slider;
@end
BullsEyeViewController.m
#import "BullsEyeViewController.h"
@interface BullsEyeViewController ()
@end
@implementation BullsEyeViewController
{
int _currentValue;
int _targetValue;
int _score;
int _round;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self startNewRound];
[self updateLabels];
}
-(void)startNewRound
{
_targetValue = 1 + arc4random_uniform(100);
_currentValue = 50;
self.slider.value = _currentValue;
[self updateLabels];
}
-(void)updateLabels
{
self.targetLabel.text = [NSString stringWithFormat:@"%d", _targetValue];
// Convert the int into a string so that it will fit in the label as an outlet
self.scoreLabel.text = [NSString stringWithFormat:@"%d", _score];
self.roundLabel.text = [NSString stringWithFormat:@"%d", _round];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(IBAction)showAlert
{
int difference = abs(_currentValue - _targetValue);
int points = 100 - difference;
_score += points;
NSString *message = [NSString stringWithFormat:@"You scored %d points", points];
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:@"Hello World"
message:message
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles: nil];
[alertView show];
[self startNewRound];
[self updateLabels];
}
-(IBAction)sliderMoved:(UISlider *)slider
{
_currentValue = lroundf(slider.value);
}
@end
错误追踪：
2013-11-19 19:59:12.299 BullsEye[13764:70b] -[UILabel intValue]: unrecognized selector sent to instance 0x8a7ef20
2013-11-19 19:59:12.351 BullsEye[13764:70b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UILabel intValue]: unrecognized selector sent to instance 0x8a7ef20'
*** First throw call stack:
(
0 CoreFoundation 0x0173a5e4 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x014bd8b6 objc_exception_throw + 44
2 CoreFoundation 0x017d7903 -[NSObject(NSObject) doesNotRecognizeSelector:] + 275
3 CoreFoundation 0x0172a90b ___forwarding___ + 1019
4 CoreFoundation 0x0172a4ee _CF_forwarding_prep_0 + 14
5 Foundation 0x0117d737 _NSSetIntValueForKeyInIvar + 46
6 Foundation 0x010eada3 _NSSetUsingKeyValueSetter + 256
7 Foundation 0x010ea253 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 267
8 Foundation 0x0114c70a -[NSObject(NSKeyValueCoding) setValue:forKeyPath:] + 412
9 UIKit 0x004cda15 -[UIRuntimeOutletConnection connect] + 106
10 libobjc.A.dylib 0x014cf7d2 -[NSObject performSelector:] + 62
11 CoreFoundation 0x01735b6a -[NSArray makeObjectsPerformSelector:] + 314
12 UIKit 0x004cc56e -[UINib instantiateWithOwner:options:] + 1417
13 UIKit 0x0033e605 -[UIViewController _loadViewFromNibNamed:bundle:] + 280
14 UIKit 0x0033edad -[UIViewController loadView] + 302
15 UIKit 0x0033f0ae -[UIViewController loadViewIfRequired] + 78
16 UIKit 0x0033f5b4 -[UIViewController view] + 35
17 UIKit 0x002679fd -[UIWindow addRootViewControllerViewIfPossible] + 66
18 UIKit 0x00267d97 -[UIWindow _setHidden:forced:] + 312
19 UIKit 0x0026802d -[UIWindow _orderFrontWithoutMakingKey] + 49
20 UIKit 0x0027289a -[UIWindow makeKeyAndVisible] + 65
21 UIKit 0x00225cd0 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1851
22 UIKit 0x0022a3a8 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 824
23 UIKit 0x0023e87c -[UIApplication handleEvent:withNewEvent:] + 3447
24 UIKit 0x0023ede9 -[UIApplication sendEvent:] + 85
25 UIKit 0x0022c025 _UIApplicationHandleEvent + 736
26 GraphicsServices 0x036e12f6 _PurpleEventCallback + 776
27 GraphicsServices 0x036e0e01 PurpleEventCallback + 46
28 CoreFoundation 0x016b5d65 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53
29 CoreFoundation 0x016b5a9b __CFRunLoopDoSource1 + 523
30 CoreFoundation 0x016e077c __CFRunLoopRun + 2156
31 CoreFoundation 0x016dfac3 CFRunLoopRunSpecific + 467
32 CoreFoundation 0x016df8db CFRunLoopRunInMode + 123
33 UIKit 0x00229add -[UIApplication _run] + 840
34 UIKit 0x0022bd3b UIApplicationMain + 1225
35 BullsEye 0x0000219d main + 141
36 libdyld.dylib 0x01d7870d start + 1
37 ??? 0x00000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
答案 0 :(得分：0)
这两行显示错误跟踪中的错误：
2013-11-19 19:59:12.299 BullsEye[13764:70b] -[UILabel intValue]: unrecognized selector sent to instance 0x8a7ef20
2013-11-19 19:59:12.351 BullsEye[13764:70b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UILabel intValue]: unrecognized selector sent to instance 0x8a7ef20'
看来您的错误不是由您发布的代码引起的，而是您所拥有的代码：
[UILabel intValue];
无论您使用上面的代码，在尝试获取{{1}的UILabel属性的整数值时，都会尝试获取text的整数值。 }}。
因此，假设您的标签名称为“myLabel：”
UILabel