分配具有一对一关系的变量时的核心数据错误

时间:2010-05-18 15:51:09

标签: iphone objective-c core-data exc-bad-access

我尝试为托管对象(C)分配其属性另一个托管对象(B)(一对一关系),其中该另一个托管对象(B)与另一个托管对象具有多对多关系对象(A)。这个分配有一个错误,我按如下方式复制:

#0  0x020e53a7 in ___forwarding___
#1  0x020c16c2 in __forwarding_prep_0___
#2  0x02078988 in CFRetain
#3  0x0207a728 in CFSetAddValue
#4  0x020c2fb2 in CFSetCreate
#5  0x01e51ce8 in -[_NSFaultingMutableSet copyWithZone:]
#6  0x020afcca in -[NSObject copy]
#7  0x01e50d22 in -[NSManagedObject(_NSInternalMethods) _newPropertiesForRetainedTypes:andCopiedTypes:preserveFaults:]
#8  0x01e51aa0 in -[NSManagedObject(_NSInternalMethods) _newAllPropertiesWithRelationshipFaultsIntact__]
#9  0x01e519b4 in -[NSManagedObjectContext(_NSInternalChangeProcessing) _establishEventSnapshotsForObject:]
#10 0x01e51866 in _PFFastMOCObjectWillChange
#11 0x01e516c5 in _PF_ManagedObject_WillChangeValueForKeyIndex
#12 0x01e51525 in _sharedIMPL_setvfk_core
#13 0x01e51483 in _PF_Handler_Public_SetProperty
#14 0x01e546d1 in -[NSManagedObject(_NSInternalMethods) _didChangeValue:forRelationship:named:withInverse:]
#15 0x0030ec1e in NSKVONotify
#16 0x002aae2a in -[NSObject(NSKeyValueObserverNotification) didChangeValueForKey:]
#17 0x01e5212f in _PF_ManagedObject_DidChangeValueForKeyIndex
#18 0x01e515b1 in _sharedIMPL_setvfk_core
#19 0x01e55827 in _svfk_5

我不太清楚这个错误的确切描述是什么。有人可以向我解释它是什么以及如何解决这个问题。请注意,托管对象B中没有任何A项的所有其他分配不会引发此错误。

ObjectC *objectC = [NSEntityDescription insertNewObjectForEntityForName:@"ObjectC" inManagedObjectContext:managedObjectContext];
objectC.objectB = objectB;

提前谢谢。

我添加了一些NSZombieEnabled / MallocStackLogging生成的日志:

2010-05-18 17:28:05.327 Foo[2069:207] *** -[CFSet retain]: message sent to deallocated instance 0x800c880
(gdb) shell malloc_history 207 0x800c880
malloc_history cannot examine process 207 because the process does not exist.
(gdb) shell malloc_history 2069 0x800c880

ALLOC 0x800c880-0x800c884 [size=5]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlIOParseDTD | _endElementNs | -[Parser parser:didEndElement:namespaceURI:qualifiedName:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asl_set_query | strdup | malloc | malloc_zone_malloc 
----
FREE  0x800c880-0x800c884 [size=5]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlIOParseDTD | _endElementNs | -[Parser parser:didEndElement:namespaceURI:qualifiedName:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asl_free | free 

ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asl_set_query | asprintf | malloc | malloc_zone_malloc 
----
FREE  0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asl_set_query | free 

ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asprintf | malloc | malloc_zone_malloc 
----
FREE  0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | free 

ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asprintf | malloc | malloc_zone_malloc 
----
FREE  0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | free 

ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asprintf | malloc | malloc_zone_malloc 
----
FREE  0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | free 

ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asprintf | malloc | malloc_zone_malloc 
----
FREE  0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | free 

ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asprintf | malloc | malloc_zone_malloc 
----
FREE  0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | free 

ALLOC 0x800c700-0x800c893 [size=404]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlIOParseDTD | _startElementNs | -[Parser parser:didStartElement:namespaceURI:qualifiedName:attributes:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | CFCalendarDecomposeAbsoluteTime | _CFCalendarDecomposeAbsoluteTimeV | __CFCalendarSetupCal | __CFCalendarCreateUCalendar | ucal_open | icu::Calendar::createInstance(icu::TimeZone*, icu::Locale const&, UErrorCode&) | malloc | malloc_zone_malloc 
----
FREE  0x800c700-0x800c893 [size=404]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlIOParseDTD | _startElementNs | -[Parser parser:didStartElement:namespaceURI:qualifiedName:attributes:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | _CFRelease | free 

ALLOC 0x800c880-0x800c8c7 [size=72]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlIOParseDTD | _startElementNs | -[Parser parser:didStartElement:namespaceURI:qualifiedName:attributes:] | +[NSEntityDescription insertNewObjectForEntityForName:inManagedObjectContext:] | +[NSManagedObject(_PFDynamicAccessorsAndPropertySupport) allocWithEntity:] | _PFAllocateObject | malloc_zone_calloc 
----
FREE  0x800c880-0x800c8c7 [size=72]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __CFRunLoopDoObservers | _performRunLoopAction | -[_PFManagedObjectReferenceQueue _processReferenceQueue:] | _PFDeallocateObject | malloc_zone_free 

ALLOC 0x800c880-0x800c8a7 [size=40]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __CFRunLoopDoObservers | CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) | CA::Transaction::commit() | CA::Context::commit_transaction(CA::Transaction*) | CALayerDisplayIfNeeded | -[TileLayer display] | -[CALayer _display] | CABackingStoreUpdate | backing_callback(CGContext*, void*) | WebCore::TiledSurface::drawLayer(CALayer*, CGContext*) | WKWindowDrawRect | WKViewDisplayRect | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | -[WebHTMLView drawSingleRect:] | -[WebFrame(WebInternal) _drawRect:contentsOnly:] | WebCore::FrameView::paintContents(WebCore::GraphicsContext*, WebCore::IntRect const&) | WebCore::RenderLayer::paint(WebCore::GraphicsContext*, WebCore::IntRect const&, WebCore::PaintRestriction, WebCore::RenderObject*) | WebCore::RenderLayer::paintLayer(WebCore::RenderLayer*, WebCore::GraphicsContext*, WebCore::IntRect const&, bool, WebCore::PaintRestriction, WebCore::RenderObject*, bool, bool) | WebCore::RenderLayer::paintLayer(WebCore::RenderLayer*, WebCore::GraphicsContext*, WebCore::IntRect const&, bool, WebCore::PaintRestriction, WebCore::RenderObject*, bool, bool) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderFlow::paintLines(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RootInlineBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::InlineFlowBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::InlineTextBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::paintTextWithShadows(WebCore::GraphicsContext*, WebCore::Font const&, WebCore::TextRun const&, int, int, WebCore::IntPoint const&, int, int, int, int, WebCore::ShadowData*, bool) | WebCore::GraphicsContext::drawText(WebCore::Font const&, WebCore::TextRun const&, WebCore::IntPoint const&, int, int) | WebCore::Font::drawSimpleText(WebCore::GraphicsContext*, WebCore::TextRun const&, WebCore::FloatPoint const&, int, int) const | WebCore::Font::drawGlyphBuffer(WebCore::GraphicsContext*, WebCore::GlyphBuffer const&, WebCore::TextRun const&, WebCore::FloatPoint&) const | WebCore::Font::drawGlyphs(WebCore::GraphicsContext*, WebCore::SimpleFontData const*, WebCore::GlyphBuffer const&, int, int, WebCore::FloatPoint const&, bool) const | CGGStateSetFont | maybeCopyTextState | calloc | malloc_zone_calloc 
----
FREE  0x800c880-0x800c8a7 [size=40]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __CFRunLoopDoObservers | CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) | CA::Transaction::commit() | CA::Context::commit_transaction(CA::Transaction*) | CALayerDisplayIfNeeded | -[TileLayer display] | -[CALayer _display] | CABackingStoreUpdate | backing_callback(CGContext*, void*) | WebCore::TiledSurface::drawLayer(CALayer*, CGContext*) | WKWindowDrawRect | WKViewDisplayRect | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | -[WebHTMLView drawSingleRect:] | -[WebFrame(WebInternal) _drawRect:contentsOnly:] | WebCore::FrameView::paintContents(WebCore::GraphicsContext*, WebCore::IntRect const&) | WebCore::RenderLayer::paint(WebCore::GraphicsContext*, WebCore::IntRect const&, WebCore::PaintRestriction, WebCore::RenderObject*) | WebCore::RenderLayer::paintLayer(WebCore::RenderLayer*, WebCore::GraphicsContext*, WebCore::IntRect const&, bool, WebCore::PaintRestriction, WebCore::RenderObject*, bool, bool) | WebCore::RenderLayer::paintLayer(WebCore::RenderLayer*, WebCore::GraphicsContext*, WebCore::IntRect const&, bool, WebCore::PaintRestriction, WebCore::RenderObject*, bool, bool) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderFlow::paintLines(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RootInlineBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::InlineFlowBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::InlineTextBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::paintTextWithShadows(WebCore::GraphicsContext*, WebCore::Font const&, WebCore::TextRun const&, int, int, WebCore::IntPoint const&, int, int, int, int, WebCore::ShadowData*, bool) | WebCore::GraphicsContext::restorePlatformState() | CGContextRestoreGState | CGGStackRestore | CGGStateRelease | textStateRelease | free 

ALLOC 0x800c880-0x800c8bf [size=64]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | CA::timer_callback(__CFRunLoopTimer*, void*) | run_animation_callbacks(double, void*) | -[UIViewAnimationState animationDidStop:finished:] | -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] | -[UINavigationTransitionView _navigationTransitionDidStop] | -[UIView(Hierarchy) removeFromSuperview] | -[UITextField resignFirstResponder] | -[UIFieldEditor resignFirstResponder] | -[UIKeyboardImpl setDelegate:] | -[UIKeyboardImpl setDelegate:force:] | -[UITextInteractionAssistant setGestureRecognizers] | -[UITextInteractionAssistant addTwoFingerRangedSelectRecognizer] | -[UILongPressGestureRecognizer initWithTarget:action:] | -[__NSPlaceholderSet init] | -[__NSPlaceholderSet initWithCapacity:] | __CFSetInit | _CFRuntimeCreateInstance | malloc_zone_malloc

2 个答案:

答案 0 :(得分:1)

错误的内容是什么?虽然堆栈跟踪很有用,但它之前的文本通常更有用。

objectC和objectB之间的关系是什么样的?它是一对一的吗?是否存在适当的倒置关系?

答案 1 :(得分:0)

哦,现在,我有了答案,根据Marcus的建议,我回头看了一下保存对象B的对象A的集合,发现我过度释放了对象A.

[objectA setValue:objectB forKey:@"objectB"];

NSError *error;
if (![managedObjectContext save:&error]){
    NSLog(@"unresolved error when saving manageObjectContext", nil);
}
[objectA release];

此消息:

*** -[CFSet retain]: message sent to deallocated instance 0x800c880

是保留一组对象失败的信号。

取消注释[objectA release]解决了错误。 :-s头疼了半天:(