Question

我正在尝试运行Apple's Scrolling Sample Code，但我得到以下错误：

Scrolling[45877:207] Unknown class ScrollingAppDelegate in Interface Builder file.
Scrolling[45877:207] Unknown class ScrollingViewController in Interface Builder file.
Scrolling[45877:207] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<UICustomObject 0x4b33330> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key viewController.'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x00f0cbe9 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x010615c2 objc_exception_throw + 47
    2   CoreFoundation                      0x00f0cb21 -[NSException raise] + 17
    3   Foundation                          0x000306cf _NSSetUsingKeyValueSetter + 135
    4   Foundation                          0x0003063d -[NSObject(NSKeyValueCoding) setValue:forKey:] + 285
    5   UIKit                               0x004af8d6 -[UIRuntimeOutletConnection connect] + 112
    6   CoreFoundation                      0x00e832cf -[NSArray makeObjectsPerformSelector:] + 239
    7   UIKit                               0x004ae2ed -[UINib instantiateWithOwner:options:] + 1041
    8   UIKit                               0x004b0081 -[NSBundle(UINSBundleAdditions) loadNibNamed:owner:options:] + 168
    9   UIKit                               0x002ba943 -[UIApplication _loadMainNibFile] + 172
    10  UIKit                               0x002bb4ca -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 291
    11  UIKit                               0x002c5db2 -[UIApplication handleEvent:withNewEvent:] + 1533
    12  UIKit                               0x002be202 -[UIApplication sendEvent:] + 71
    13  UIKit                               0x002c3732 _UIApplicationHandleEvent + 7576
    14  GraphicsServices                    0x01842a36 PurpleEventCallback + 1550
    15  CoreFoundation                      0x00eee064 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
    16  CoreFoundation                      0x00e4e6f7 __CFRunLoopDoSource1 + 215
    17  CoreFoundation                      0x00e4b983 __CFRunLoopRun + 979
    18  CoreFoundation                      0x00e4b240 CFRunLoopRunSpecific + 208
    19  CoreFoundation                      0x00e4b161 CFRunLoopRunInMode + 97
    20  UIKit                               0x002bafa8 -[UIApplication _run] + 636
    21  UIKit                               0x002c742e UIApplicationMain + 1160
    22  Scrolling                           0x0000279c main + 102
    23  Scrolling                           0x0000272d start + 53
)
terminate called after throwing an instance of 'NSException'

奇怪的是，我在MainWindow.xib（唯一的xib文件）中找不到这些连接。 Outlets正确连接到AppDelegate和MyViewController类。

Answer 1

运行时无法找到创建类“ScrollingAppDelegate”和“ScrollingViewController”的实例的方法，这些类在xib文件中被序列化。所以它默认为UICustomObject，你也没有。

您确定源文件中是否存在这些类并且它们是否已正确编译（即“编译”构建阶段的一部分）？

同时检查类的拼写和大小写。它必须匹配xib文件和源文件。

如果出现问题，xib文件中可能会出现黄色警告点（右下角）。点击它获取更多信息。

最后，示例代码标记为iOS4 +。你的设备上有iOS 4吗？

苹果的滚动示例崩溃

1 个答案: