UIWebView抛出NSUnknownKeyException iPad

Question

我有一个标签栏应用程序.一切正常,我可以切换到标签和所有内容,除非我切换到我的第二个选项卡ProductViewClass,视图不会更新,它会吐出下面的控制台输出.除了UIWebView和UILabel之外,我在此视图中没有任何内容.当我删除UIWebView它成功运行时,当我添加另一个它仍然有效.它只在我将IBOutlet从我的文件所有者连接到UIWebView时停止工作.除了合成和发布productWebView唯一的非模板代码ProductWebView.m是这样的:

    NSString *urlString = @"http://www.google.com/";
    NSURL *theURL = [NSURL URLWithString:urlString];
    NSURLRequest *urlRequest = [NSURLRequest requestWithURL:theURL];
    [productWebView loadRequest:urlRequest];
    NSLog(@"Google loaded");

ProductWebView.h的整体如下:

#import <UIKit/UIKit.h>
@interface ProductViewClass : UIViewController {

    IBOutlet UIWebView *productWebView;
}

@property(nonatomic, retain) UIWebView *productWebView;
@end

这是控制台输出:

This GDB was configured as "x86_64-apple-darwin".Attaching to process 52523.
2011-01-30 19:18:28.907 FairCom[52523:40b] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<UIViewController 0x4d06eb0> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key productWebView.'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x00da8be9 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x00efd5c2 objc_exception_throw + 47
    2   CoreFoundation                      0x00da8b21 -[NSException raise] + 17
    3   Foundation                          0x000296cf _NSSetUsingKeyValueSetter + 135
    4   Foundation                          0x0002963d -[NSObject(NSKeyValueCoding) setValue:forKey:] + 285
    5   UIKit                               0x004a88d6 -[UIRuntimeOutletConnection connect] + 112
    6   CoreFoundation                      0x00d1f2cf -[NSArray makeObjectsPerformSelector:] + 239
    7   UIKit                               0x004a72ed -[UINib instantiateWithOwner:options:] + 1041
    8   UIKit                               0x004a9081 -[NSBundle(UINSBundleAdditions) loadNibNamed:owner:options:] + 168
    9   UIKit                               0x00361a94 -[UIViewController _loadViewFromNibNamed:bundle:] + 70
    10  UIKit                               0x0035f709 -[UIViewController loadView] + 120
    11  UIKit                               0x0035f5e3 -[UIViewController view] + 56
    12  UIKit                               0x00372230 -[UITabBarController transitionFromViewController:toViewController:transition:shouldSetSelected:] + 120
    13  UIKit                               0x00370d86 -[UITabBarController transitionFromViewController:toViewController:] + 64
    14  UIKit                               0x00372b7e -[UITabBarController _setSelectedViewController:] + 263
    15  UIKit                               0x003729ed -[UITabBarController _tabBarItemClicked:] + 352
    16  UIKit                               0x002b1a6e -[UIApplication sendAction:to:from:forEvent:] + 119
    17  UIKit                               0x004af1f2 -[UITabBar _sendAction:withEvent:] + 422
    18  UIKit                               0x002b1a6e -[UIApplication sendAction:to:from:forEvent:] + 119
    19  UIKit                               0x003401b5 -[UIControl sendAction:to:forEvent:] + 67
    20  UIKit                               0x00342647 -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 527
    21  UIKit                               0x0034016c -[UIControl sendActionsForControlEvents:] + 49
    22  UIKit                               0x002b1a6e -[UIApplication sendAction:to:from:forEvent:] + 119
    23  UIKit                               0x003401b5 -[UIControl sendAction:to:forEvent:] + 67
    24  UIKit                               0x00342647 -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 527
    25  UIKit                               0x003411f4 -[UIControl touchesEnded:withEvent:] + 458
    26  UIKit                               0x002d60d1 -[UIWindow _sendTouchesForEvent:] + 567
    27  UIKit                               0x002b737a -[UIApplication sendEvent:] + 447
    28  UIKit                               0x002bc732 _UIApplicationHandleEvent + 7576
    29  GraphicsServices                    0x016dea36 PurpleEventCallback + 1550
    30  CoreFoundation                      0x00d8a064 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
    31  CoreFoundation                      0x00cea6f7 __CFRunLoopDoSource1 + 215
    32  CoreFoundation                      0x00ce7983 __CFRunLoopRun + 979
    33  CoreFoundation                      0x00ce7240 CFRunLoopRunSpecific + 208
    34  CoreFoundation                      0x00ce7161 CFRunLoopRunInMode + 97
    35  GraphicsServices                    0x016dd268 GSEventRunModal + 217
    36  GraphicsServices                    0x016dd32d GSEventRun + 115
    37  UIKit                               0x002c042e UIApplicationMain + 1160
    38  FairCom                             0x00001be0 main + 102
    39  FairCom                             0x00001b71 start + 53
    40  ???                                 0x00000001 0x0 + 1
)
terminate called after throwing an instance of 'NSException'
sharedlibrary apply-load-rules all
(gdb) 

谢谢你的帮助!

Answer 1

你正在加载一个笔尖.在那个笔尖中,你有一个名为productWebViewthe hook 的插座,可能是一个Web视图.您所看到的例外情况是告诉您插座productWebView实际上并不存在.这就是它变得奇怪的地方.该错误表示该对象<UIViewController 0x4d06eb0>是具有此缺失出口的对象.奇怪的是它所代表的位置UIViewController而不是实际视图控制器子类的名称.听起来你有一个nib,其中File的Owner被设置为你的一个视图控制器子类,但在运行时你实际上只是UIViewController直接使用一个实例.您应该验证表示选项卡栏控制器中的选项卡的所有视图控制器是否是实际正确的子类,UIViewController而不仅仅是其UIViewController自身的实例.