Swift 错误 - “发送到实例的无法识别的选择器”

Posted 2023-02-24

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【中文标题】Swift 错误 - “发送到实例的无法识别的选择器”【英文标题】：Swift Error - "Unrecognized selector sent to instance" 【发布时间】：2015-03-03 00:59:49 【问题描述】：

我正在使用 Xcode v6.1.1 开发一个 Swift 项目，我收到以下我不理解的错误。我相信我的 Main.storyboard 和/或我将它们连接到的 UILabel 变量中的几个标签存在问题。我已经尝试了所有能找到的方法来修复它，但没有任何效果。

任何帮助将不胜感激。

2015-03-02 19:43:14.854 Final Project[7380:250494] -[UILabel longValue]:  unrecognized selector sent to instance 0x7b8e1810  
2015-03-02 19:43:14.876 Final Project[7380:250494] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UILabel longValue]: unrecognized selector sent to instance 0x7b8e1810'  
*** First throw call stack:  
(
    0   CoreFoundation                      0x00686946 __exceptionPreprocess + 182  
    1   libobjc.A.dylib                     0x02062a97 objc_exception_throw + 44  
    2   CoreFoundation                      0x0068e5c5 -[NSObject(NSObject)   doesNotRecognizeSelector:] + 277  
    3   CoreFoundation                      0x005d73e7 ___forwarding___ + 1047  
    4   CoreFoundation                      0x005d6fae _CF_forwarding_prep_0 + 14  
    5   Foundation                          0x00b0b6dc _NSSetLongValueForKeyWithMethod + 69  
    6   Foundation                          0x00a691c6 _NSSetUsingKeyValueSetter + 257  
    7   Foundation                          0x00a690bd -[NSObject(NSKeyValueCoding) setValue:forKey:] + 267  
    8   Foundation                          0x00a9e9a6 -[NSObject(NSKeyValueCoding) setValue:forKeyPath:] + 386  
    9   UIKit                               0x011cf649 -[UIRuntimeOutletConnection connect] + 106  
    10  libobjc.A.dylib                     0x02078724 -[NSObject performSelector:] + 62  
    11  CoreFoundation                      0x005c05dc -[NSArray makeObjectsPerformSelector:] + 316  
    12  UIKit                               0x011ce10a -[UINib instantiateWithOwner:options:] + 1775  
    13  UIKit                               0x00ff0624 -[UIViewController _loadViewFromNibNamed:bundle:] + 270  
    14  UIKit                               0x00ff0dbb -[UIViewController loadView] + 295  
    15  UIKit                               0x00ff0fef -[UIViewController loadViewIfRequired] + 78  
    16  UIKit                               0x00ff1595 -[UIViewController view] + 35  
    17  UIKit                               0x01664707 -[_UIFullscreenPresentationController _setPresentedViewController:] + 75  
    18  UIKit                               0x00fc6a81 -[UIPresentationController initWithPresentedViewController:presentingViewController:] + 113  
    19  UIKit                               0x00ffea61 -[UIViewController _presentViewController:withAnimationController:completion:] + 2102  
    20  UIKit                               0x010015d2 __62-[UIViewController presentViewController:animated:completion:]_block_invoke + 345  
    21  UIKit                               0x01001424 -[UIViewController presentViewController:animated:completion:] + 224  
    22  UIKit                               0x010060be -[UIViewController _showViewController:withAction:sender:] + 213  
    23  UIKit                               0x012423b5 -[UIStoryboardShowSegue perform] + 143  
    24  UIKit                               0x014b6b49 -[UIStoryboardSegueTemplate _perform:] + 217  
    25  UIKit                               0x014b6bc5 -[UIStoryboardSegueTemplate perform:] + 116  
    26  libobjc.A.dylib                     0x020787cd -[NSObject performSelector:withObject:withObject:] + 84  
    27  UIKit                               0x00e9b23d -[UIApplication sendAction:to:from:forEvent:] + 99  
    28  UIKit                               0x00e9b1cf -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 64  
    29  UIKit                               0x00fcee86 -[UIControl sendAction:to:forEvent:] + 69  
    30  UIKit                               0x00fcf2a3 -[UIControl _sendActionsForEvents:withEvent:] + 598  
    31  UIKit                               0x00fce50d -[UIControl touchesEnded:withEvent:] + 660  
    32  UIKit                               0x00eeb60a -[UIWindow _sendTouchesForEvent:] + 874  
    33  UIKit                               0x00eec0e5 -[UIWindow sendEvent:] + 791  
    34  UIKit                               0x00eb1549 -[UIApplication sendEvent:] + 242  
    35  UIKit                               0x00ec137e _UIApplicationHandleEventFromQueueEvent + 20690  
    36  UIKit                               0x00e95b19 _UIApplicationHandleEventQueue + 2206  
    37  CoreFoundation                      0x005aa1df __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15  
    38  CoreFoundation                      0x0059fced __CFRunLoopDoSources0 + 253  
    39  CoreFoundation                      0x0059f248 __CFRunLoopRun + 952  
    40  CoreFoundation                      0x0059ebcb CFRunLoopRunSpecific + 443  
    41  CoreFoundation                      0x0059e9fb CFRunLoopRunInMode + 123  
    42  GraphicsServices                    0x0441a24f GSEventRunModal + 192  
    43  GraphicsServices                    0x0441a08c GSEventRun + 104  
    44  UIKit                               0x00e998b6 UIApplicationMain + 1526  
    45  Final Project                       0x000e904e top_level_code + 78  
    46  Final Project                       0x000e908b main + 43  
    47  libdyld.dylib                       0x027cfac9 start + 1  
)  
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

【问题讨论】：

【参考方案1】：

你忘记了字符串名称中的 : 吗？

你的班级是否标有@objc？

【讨论】：

【参考方案2】：

只需查看-[UILabel longValue]: unrecognized selector sent to instance 0x7b8e1810 即可给我答案。您将UILabel 视为NSString。

在你的代码中某处你有[label longValue]，你的意思是有[label.text longValue]。

查看更多调用堆栈后。我可以看到它在从情节提要初始化视图控制器时发生。

您是否对任何视图进行了子类化？您可能无意中将属性的类型从 NSString 更改为 UILabel。

【讨论】：

【参考方案3】：