字典和 label.text 未捕获的异常

Question

我尝试在字典中搜索（通过观察者传递）：

NSDictionary *myDictionnary = [NSDictionary dictionaryWithObjectsAndKeys:@"details",@"details de l'installation",@"recapitulatif",@"recapitulatif de l'installe",nil];

...在标签中设置文本：

NSLog(@"key: %@, value: %@", recapitulatif, [dictionnary objectForKey:@"recapitulatif"]);
details.text = [dictionnary objectForKey:@"recapitulatif"];

但这使我成为一个未捕获的异常：

-[ThirdViewController objectForKey:]: unrecognized selector sent to instance 0x4b59c30
2012-01-09 15:07:13.179 emars[8185:b303] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[ThirdViewController objectForKey:]: unrecognized selector sent to instance 0x4b59c30'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x00fb45a9 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x01108313 objc_exception_throw + 44
    2   CoreFoundation                      0x00fb60bb -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
    3   CoreFoundation                      0x00f25966 ___forwarding___ + 966
    4   CoreFoundation                      0x00f25522 _CF_forwarding_prep_0 + 50
    5   emars                               0x0000439d -[FirstViewController updateLabel:] + 134
    6   Foundation                          0x0002f669 _nsnote_callback + 145
    7   CoreFoundation                      0x00f8c9f9 __CFXNotificationPost_old + 745
    8   CoreFoundation                      0x00f0b93a _CFXNotificationPostNotification + 186
    9   Foundation                          0x0002520e -[NSNotificationCenter postNotificationName:object:userInfo:] + 134
    10  emars                               0x0000880b -[ThirdViewController connectionDidFinishLoading:] + 541

感谢帮助我，我不明白我的错误

编辑：

这是整个方法：

- (void)updateLabel:(NSNotification*)notification
{
    NSDictionary *dictionnary = (NSDictionary*)[notification object];   
    NSLog(@"key: %@, value: %@", recapitulatif, [dictionnary objectForKey:@"recapitulatif"]);
}

观察者是从“ThirdViewController”类发送的：

NSDictionary *myDictionnary = [NSDictionary dictionaryWithObjectsAndKeys:@"details",@"details de l'installation",@"recapitulatif",@"recapitulatif de l'installe",nil];
[[NSNotificationCenter defaultCenter] postNotificationName:@"LABELUPDATENOTIFICATION" object:self userInfo:myDictionnary];

再次感谢！

编辑2：

- (void)updateLabel:(NSNotification*)notification
{
    NSDictionary *dictionnary = (NSDictionary*)[notification userInfo];
    NSLog(@"key: %@, value: %@", recapitulatif, [dictionnary objectForKey:@"recapitulatif"]);   
    NSLog(@"text: ", [dictionnary objectForKey:@"recapitulatif"]);
}

给我

key: <UILabel: 0x4b2ff80; frame = (20 245; 280 133); text = 'Index du Compteur: 1 572,...'; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <CALayer: 0x4b30040>>, value: (null)

，

text: 

这应该给我@“recapitulatif de l'installe”，不是吗？

Answer 1

从您发布的错误（但没有看到更多代码，您应该也在那里发布）来看，您似乎正在尝试在 objectForKey 上执行 objectForKey 方法code>ThirdViewController 对象（这是一个视图控制器），而不是您想要从中获取对象的实际 NSDictionary 。

当您调用 objectForKey 时，请确保 dictionnary 设置正确。

这样做：

NSDictionary *dictionnary = (NSDictionary*)[notification userInfo];  

而不是这样做：

NSDictionary *dictionnary = (NSDictionary*)[notification object];   

我链接了苹果的 NSDictionary userInfo 文档。