iPhone - 在 NSMutableArray 上使用 addObject 时发生崩溃

Question

我这里有个问题。或者也许我真的很累......

我有课:

@interface THECLASS : UIViewController <UITableViewDelegate> {
    NSMutableArray* param;
}

@property(nonatomic, retain) NSMutableArray* param;

在该类中，我有一个方法，当用户单击 tableViewCell 内的 UISwitch 时调用该方法(我将参数构建到此处未显示的 IBAction 方法中):

@synthesize param;

- (void) changedSelectorValue:(NSIndexPath*)indexPath isOn:(BOOL)isOn {
    [self.param addObject:@"eeeee"];
}

这会使应用程序崩溃并显示以下日志:

2011-02-04 01:31:02.548 Learning Project[3895:207] -[__NSArrayI addObject:]: unrecognized selector sent to instance 0x630c960
2011-02-04 01:31:02.549 Learning Project[3895:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSArrayI addObject:]: unrecognized selector sent to instance 0x630c960'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x00fc4be9 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x011195c2 objc_exception_throw + 47
    2   CoreFoundation                      0x00fc66fb -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
    3   CoreFoundation                      0x00f36366 ___forwarding___ + 966
    4   CoreFoundation                      0x00f35f22 _CF_forwarding_prep_0 + 50
    5   Learning Project                    0x00019463 -[ChoixJoursDisponibiliteController changedSelectorValue:isOn:] + 644
    6   Learning Project                    0x000190db -[ChoixJoursDisponibiliteController clickChangedSelectorValue:] + 307
    7   UIKit                               0x002f6a6e -[UIApplication sendAction:to:from:forEvent:] + 119
    8   UIKit                               0x003851b5 -[UIControl sendAction:to:forEvent:] + 67
    9   UIKit                               0x00387647 -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 527
    10  UIKit                               0x004c9c6d -[UISwitch _onAnimationDidStop:finished:context:] + 201
    11  UIKit                               0x00327665 -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 294
    12  UIKit                               0x003274f7 -[UIViewAnimationState animationDidStop:finished:] + 77
    13  QuartzCore                          0x01eab6cb _ZL23run_animation_callbacksdPv + 278
    14  QuartzCore                          0x01eab589 _ZN2CAL14timer_callbackEP16__CFRunLoopTimerPv + 157
    15  CoreFoundation                      0x00fa5fe3 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 19
    16  CoreFoundation                      0x00fa7594 __CFRunLoopDoTimer + 1220
    17  CoreFoundation                      0x00f03cc9 __CFRunLoopRun + 1817
    18  CoreFoundation                      0x00f03240 CFRunLoopRunSpecific + 208
    19  CoreFoundation                      0x00f03161 CFRunLoopRunInMode + 97
    20  GraphicsServices                    0x018f9268 GSEventRunModal + 217
    21  GraphicsServices                    0x018f932d GSEventRun + 115
    22  UIKit                               0x0030542e UIApplicationMain + 1160
    23  Learning Project                    0x00002580 main + 102
    24  Learning Project                    0x00002511 start + 53
    25  ???                                 0x00000001 0x0 + 1
)
terminate called after throwing an instance of 'NSException'

参数是从调用者 View 中填充的，例如:

NSMutableArray* filledArray = [NSMutableArray arrayWithObjects:@"SOME TEXT", nil] 
nextController.param = filledArray;

NSLog(@"%@", self.param); 在崩溃之前给出:

2011-02-04 02:01:17.205 Learning Project[4223:207] (
    "JOURDISPO_MARDI"
)

为什么会崩溃？数组在那里，填充而不是零...它似乎定义良好... addObject 是一个 NSMutableArray 方法...我不明白

我没有在这里显示它，但与removeObject有相同的日志。

Answer 1

答案隐藏在“已接受”答案的评论中。我从 Google 来到这里，它解决了我的问题，所以……根据 @e.James 的评论，让事情变得更清楚:

When you implement the "NSCopying" protocol, and implement "copyWithZone", you MUST NOT use "copy" on your internal mutable arrays - this DOES NOT copy the array (instead, it creates a non-mutable copy).

例如来 self 自己的代码:

// Class: MyClass

@property(nonatomic, retain) NSMutableArray* mutArray;

-(id)copyWithZone:(NSZone *)zone
{
    MyClass* other = [[MyClass alloc] init];

//  other.mutArray = [self.mutArray copy]; // WRONG!
    other.mutArray = [self.mutArray mutableCopy]; // CORRECT!

    return other;
}