setObject：ForKey：crash？ [英] setObject:ForKey: crash?

问题描述

我在控制台中收到此崩溃：

  2011-08-27 23：26：45.041应用[1672： 3117] ***由于未捕获异常而终止应用程序'NSInvalidArgumentException'，reason：' -  [__ NSCFDictionary setObject：forKey：]：尝试插入nil键'
 ***第一次调用堆栈：
 
终止调用抛出异常[切换到进程10243线程0x2803] 
 [切换到进程10243线程0x2803] 
  

我认为在崩溃时，与这个崩溃有关的唯一一行是这行：

  UIImage * photo = [self.selectedDictionary objectForKey：@ProfileImage]; 
  

这里有什么问题吗？可能是什么问题？

Edit1：
当我这样做来调用一个方法时崩溃：
代码：

  if（actionSheet.tag == 1）{
 [self showAchievements]; 
} 
  

这是showAchievements方法：
代码：

   - （void）showAchievements {
 GKAchievementViewController * achievement = [[GKAchievementViewController alloc] init]; 
 if（achievements！= nil）
 {
 achievement.achievementDelegate = self; 
 [self presentModalViewController：achievements animated：YES]; 
} 
} 
 
  - （void）achievementViewControllerDidFinish：（GKAchievementViewController *）viewController 
 {
 [self dismissModalViewControllerAnimated：YES]; 
 [viewController release]; 
} 
  

这次崩溃可能是因为我没有在iTC中正确挂钩

有没有任何想法？

Edit2：我在这里，在我的控制台，就在它崩溃之前，它有一行缺少方法。所以我搜索这个NSLog的位置，它在GameCenterManager.m，一个游戏中心我认为必要的文件。这里是方法：

   - （void）callDelegate：（SEL）selector withArg：（id）arg error：（NSError * ）err 
 {
 assert（[NSThread isMainThread]）; 
 if（[delegate respondingToSelector：selector]）
 {
 if（arg！= NULL）
 {
 [delegate performSelector：selector withObject：arg withObject：err] ; 
} 
 else 
 {
 [delegate performSelector：selector withObject：err]; 
} 
} 
 else 
 {
 NSLog（@Missed Method）; 
} 
} 
  

那么从代码中你会看到什么错误？ / p>

谢谢！

解决方案

在您发布的代码中：

 原因：' -  [__ NSCFDictionary setObject：forKey：]：尝试插入nil键'
  

不能将nil键插入字典。你在做什么像[myDictionary setObject：foo forKey：bar]其中'bar'是nil？

顺便说一下，你也不能将nil值插入字典，但是这似乎不是错误原因所指示的。您可以呼叫 [myDictionary setValue：nil forKey：bar] （只要bar不为nil） 。如果你想指明一个nil值，你可以将 NSNull 对象插入字典。但是键 - 键必须始终为非零。

I am getting this crash in the console:

2011-08-27 23:26:45.041 App[1672:3117] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFDictionary setObject:forKey:]: attempt to insert nil key'
*** First throw call stack:
(0x3231c8c3 0x362ee1e5 0x3231c7bd 0x3231c7df 0x32289679 0x3052e865 0x3220fd55 0x3221b7a3 0x3345e4b7 0x3345e38c)
terminate called throwing an exception[Switching to process 10243 thread 0x2803]
[Switching to process 10243 thread 0x2803]

The only line that I think would fire at the time it crashes that relates to this crash is this line:

UIImage *photo = [self.selectedDictionary objectForKey:@"ProfileImage"];

Does anything look wrong here? What could be the problem?

Edit1: It is crashing when I do this to call a method: Code:

if(actionSheet.tag == 1) {
            [self showAchievements];
        }

This is the showAchievements method: Code:

- (void)showAchievements {
    GKAchievementViewController *achievements = [[GKAchievementViewController alloc] init];
    if (achievements != nil)
    {
        achievements.achievementDelegate = self;
        [self presentModalViewController:achievements animated:YES];
    }
}

- (void)achievementViewControllerDidFinish:(GKAchievementViewController *)viewController
{
    [self dismissModalViewControllerAnimated:YES];
    [viewController release];
}

Can this crash be because I have not properly hooked everything up in iTC? I am definitely sure it crashes in that method and I do not know why.

Does anyone have any ideas?

Edit2: I am getting down to it here, in my console, right before it crashes it has a line saying Missed Method. So I search for where this NSLog is and it is in GameCenterManager.m, a file necessary for Game Center I think. Here is the method:

    - (void) callDelegate: (SEL) selector withArg: (id) arg error: (NSError*) err
{
    assert([NSThread isMainThread]);
    if([delegate respondsToSelector: selector])
    {
        if(arg != NULL)
        {
            [delegate performSelector: selector withObject: arg withObject: err];
        }
        else
        {
            [delegate performSelector: selector withObject: err];
        }
    }
    else
    {
        NSLog(@"Missed Method");
    }
}

So from that code do you see whats wrong?

Thanks!

解决方案

I'd guess the answer is right there in the code you posted:

reason: '-[__NSCFDictionary setObject:forKey:]: attempt to insert nil key'

You can't insert a nil key into a dictionary. Are you doing something like [myDictionary setObject:foo forKey:bar] where 'bar' is nil?

Incidentally, you also can't insert nil values into a dictionary, but that doesn't appear to be what the error reason indicates. You can call [myDictionary setValue:nil forKey:bar] (as long as bar isn't nil) - this removes the key from the dictionary. And if you want to indicate a "nil" value, you can insert the NSNull object into a dictionary. But keys -- keys must always be non-nil.

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