iPhone - 在 NSMutableArray 上使用 addObject 崩溃 [英] iPhone - Crash using addObject on a NSMutableArray

问题描述

我这里有问题.又或许我真的很累……

I have a problem here. Or Maybe I'm really tired...

我有一堂课:

@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):

Inside that class I have a method that is called when the user clicks on a UISwitch inside a tableViewCell (I build the params into a IBAction method that is not shwon here) :

@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:

This crashes the app with the following log :

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'

param 由调用者视图填充，例如:

param is filled from a caller view by something like :

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nil...看起来定义很好... addObject 是一个NSMutableArray 方法...我不明白

Why does this crash ? The array is there, filled and not nil... It seems well defined... addObject is a NSMutableArray method... I don't understand

我这里没有展示，但是和removeObject有相同的日志.

I don't show it here but there is the same log with removeObject.

推荐答案

你的属性被定义为 retain，你说 param 是从来电者视图".这可能是你的问题.

Your property is defined as retain, and you say that param is "a filled array from the caller view". This could be your problem.

例如，如果您执行以下操作:

For example, if you do the following:

NSArray * filledArray = [NSArray arrayWithObjects:..., nil];
theClassInstance.param = filledArray;

您将保留一个非可变数组.

You will have retained a non-mutable array.

要调试 param 的设置，您可以在 .m 中执行以下操作:

To debug the setting of param, you could do the following in your .m:

@dynamic param;
- (NSMutableArray*)param { return param; }
- (void)setParam:(NSMutableArray*)newArray {
    NSLog(@"setting new param from class: %@",
          NSStringFromClass([newArray class]));
    [newArray retain];
    [param release];
    param = newArray;
}

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