NSUnknownKeyException', reason: '[<UIApplication 0x8a58320> setValue:forUndefinedKey:]

 今天，在xcode5上想试下如何新建一个*.xib和UIviewControl结合起来，所以新建了一个空的iPhone项目。然后新建了一个xib文件和一个继承自UIViewControl的类。

 在Appledelegate.m文件中添加如下代码

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];    // Override point for customization after application launch.    self.window.backgroundColor = [UIColor whiteColor];    [self.window makeKeyAndVisible];    //添加的代码    myTestViewController *myTest = [[myTestViewController alloc] initWithNibName:@"myTestView" bundle:nil];        self.window.rootViewController = myTest;    //[myTest release];//开启了ARC，会自动释放内容    return YES;}

按正确的方法进行文件关联，然后编译运行出现如下错误：

014-04-02 10:32:53.264 myTest01[751:70b] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<UIApplication 0x8a58320> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key view.'*** First throw call stack:(    0   CoreFoundation                      0x017345e4 __exceptionPreprocess + 180    1   libobjc.A.dylib                     0x014b78b6 objc_exception_throw + 44    2   CoreFoundation                      0x017c46a1 -[NSException raise] + 17    3   Foundation                          0x01178c2e -[NSObject(NSKeyValueCoding) setValue:forUndefinedKey:] + 282    4   Foundation                          0x010e4f3b _NSSetUsingKeyValueSetter + 88    5   Foundation                          0x010e4493 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 267    6   Foundation                          0x0114694a -[NSObject(NSKeyValueCoding) setValue:forKeyPath:] + 412    7   UIKit                               0x004cbcd5 -[UIRuntimeOutletConnection connect] + 106    8   libobjc.A.dylib                     0x014c97d2 -[NSObject performSelector:] + 62    9   CoreFoundation                      0x0172fb6a -[NSArray makeObjectsPerformSelector:] + 314    10  UIKit                               0x004ca82e -[UINib instantiateWithOwner:options:] + 1417    11  UIKit                               0x004cc5bb -[NSBundle(UINSBundleAdditions) loadNibNamed:owner:options:] + 165    12  UIKit                               0x00229fcb -[UIApplication _loadMainNibFileNamed:bundle:] + 58    13  UIKit                               0x0022a2f9 -[UIApplication _loadMainInterfaceFile] + 245    14  UIKit                               0x00228e9f -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 543    15  UIKit                               0x0023d42c -[UIApplication handleEvent:withNewEvent:] + 3447    16  UIKit                               0x0023d999 -[UIApplication sendEvent:] + 85    17  UIKit                               0x0022ac35 _UIApplicationHandleEvent + 736    18  GraphicsServices                    0x036d72eb _PurpleEventCallback + 776    19  GraphicsServices                    0x036d6df6 PurpleEventCallback + 46    20  CoreFoundation                      0x016afdd5 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53    21  CoreFoundation                      0x016afb0b __CFRunLoopDoSource1 + 523    22  CoreFoundation                      0x016da7ec __CFRunLoopRun + 2156    23  CoreFoundation                      0x016d9b33 CFRunLoopRunSpecific + 467    24  CoreFoundation                      0x016d994b CFRunLoopRunInMode + 123    25  UIKit                               0x002286ed -[UIApplication _run] + 840    26  UIKit                               0x0022a94b UIApplicationMain + 1225    27  myTest01                            0x0000305d main + 141    28  libdyld.dylib                       0x01d72701 start + 1    29  ???                                 0x00000001 0x0 + 1)libc++abi.dylib: terminating with uncaught exception of type NSException

网上有很多解决这个问题的方案，尝试了很多都没用。让后发现在*.plist文件里面有个Main nib file base name，把这个去掉就可以了