NSArrayController 通过 NSKeyedUnarchiveFromData 值转换器绑定到 NSUserDefaults

Question

我有一个绑定到共享用户默认控制器的 NSArrayController 实例。 （见下面的截图）关键路径指向 NSData 的一个实例，当解压时应该给出一个数组。但是当笔尖开始加载时，它给出 -

2011-07-10 23:55:23.093 MyApp[18139:507] -[__NSCFConstantString characterAtIndex:]: Range or index out of bounds
2011-07-10 23:55:23.106 MyApp[18139:507] (
    0   CoreFoundation                      0x00007fff95729986 __exceptionPreprocess + 198
    1   libobjc.A.dylib                     0x00007fff90d5dd5e objc_exception_throw + 43
    2   CoreFoundation                      0x00007fff957297ba +[NSException raise:format:arguments:] + 106
    3   CoreFoundation                      0x00007fff95729744 +[NSException raise:format:] + 116
    4   CoreFoundation                      0x00007fff956e750e -[__NSCFString characterAtIndex:] + 94
    5   Foundation                          0x00007fff94c090a7 NSKeyValuePropertyForIsaAndKeyPathInner + 109
    6   Foundation                          0x00007fff94c08d43 NSKeyValuePropertyForIsaAndKeyPath + 159
    7   Foundation                          0x00007fff94c08afb -[NSObject(NSKeyValueObserverRegistration) addObserver:forKeyPath:options:context:] + 82
    8   Foundation                          0x00007fff94c3f5a0 -[NSKeyValueNestedProperty object:didAddObservance:recurse:] + 222
    9   Foundation                          0x00007fff94c0a177 -[NSObject(NSKeyValueObserverRegistration) _addObserver:forProperty:options:context:] + 481
    10  Foundation                          0x00007fff94c08b18 -[NSObject(NSKeyValueObserverRegistration) addObserver:forKeyPath:options:context:] + 111
    11  AppKit                              0x00007fff95beddd1 -[NSAutounbinder addObserver:forKeyPath:options:context:] + 210
    12  AppKit                              0x00007fff95a1e323 -[NSBinder _updateObservingRegistration:] + 859
    13  AppKit                              0x00007fff95a1d4a1 -[NSBinder establishConnection] + 314
    14  AppKit                              0x00007fff95a1185b -[NSObject(NSKeyValueBindingCreation) bind:toObject:withKeyPath:options:] + 591
    15  AppKit                              0x00007fff95a0ab81 -[NSIBObjectData nibInstantiateWithOwner:topLevelObjects:] + 1079
    16  AppKit                              0x00007fff95a011b9 loadNib + 322
    17  AppKit                              0x00007fff95a006b6 +[NSBundle(NSNibLoading) _loadNibFile:nameTable:withZone:ownerBundle:] + 217
    18  AppKit                              0x00007fff95a005d1 +[NSBundle(NSNibLoading) loadNibFile:externalNameTable:withZone:] + 141
    19  AppKit                              0x00007fff95bee328 -[NSWindowController loadWindow] + 221
    20  AppKit                              0x00007fff95bee0e3 -[NSWindowController window] + 75
    21  AppKit                              0x00007fff95bedf51 -[NSWindowController showWindow:] + 40
    22  MyApp                               0x00000001000024af -[MyAppDelegate showPreferencesWindow:] + 255
    23  MyApp                               0x0000000100005229 -[TBStatusWindowController preferences:] + 89
    24  CoreFoundation                      0x00007fff9571911d -[NSObject performSelector:withObject:] + 61
    25  AppKit                              0x00007fff95afd852 -[NSApplication sendAction:to:from:] + 139
    26  AppKit                              0x00007fff95afd784 -[NSControl sendAction:to:] + 88
    27  AppKit                              0x00007fff95afd6af -[NSCell _sendActionFrom:] + 137
    28  AppKit                              0x00007fff95afcb7a -[NSCell trackMouse:inRect:ofView:untilMouseUp:] + 2014
    29  AppKit                              0x00007fff95b7c57c -[NSButtonCell trackMouse:inRect:ofView:untilMouseUp:] + 489
    30  AppKit                              0x00007fff95afb786 -[NSControl mouseDown:] + 786
    31  AppKit                              0x00007fff95ac666e -[NSWindow sendEvent:] + 6280
    32  AppKit                              0x00007fff95a5ef19 -[NSApplication sendEvent:] + 5665
    33  AppKit                              0x00007fff959f542b -[NSApplication run] + 548
    34  AppKit                              0x00007fff95c7352a NSApplicationMain + 867
    35  MyApp                               0x0000000100001a40 main + 32
    36  MyApp                               0x0000000100001a14 start + 52
)

那么我的配置有什么问题？

Answer 1

为什么空的 NSData 对象反序列化为空的 NSArray ？没有数据，因此解档器甚至不知道您的对象属于哪个类。如果您想取消归档一个空的 NSArray，您必须先归档一个空的 NSArray。这不会导致空的 NSData。

Answer 2

问题的原因与此完全无关。事实证明我的配置没有问题。

谢谢你的时间，奥兹。