為什么這些錯誤在Xcode中意味着什么？

Question

2009-07-06 06:49:13.666 Spark[9825:10b] -[<NSUserDefaultsController 0x137af0> valueForUndefinedKey:]: this class is not key value coding-compliant for the key hotKeyDisplayEntry.

2009-07-06 06:49:13.667 Spark[9825:10b] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<NSUserDefaultsController 0x137af0> valueForUndefinedKey:]: this class is not key value coding-compliant for the key hotKeyDisplayEntry.'

編輯：我認為引起了問題。

OSStatus MyHotKeyHandler(EventHandlerCallRef nextHandler,EventRef theEvent,void *userData)
{
    EventHotKeyID hkCom;
    GetEventParameter(theEvent,kEventParamDirectObject,typeEventHotKeyID,NULL,sizeof(hkCom),NULL,&hkCom);
    HotKeyController *controller = (HotKeyController *)userData;
    int l = hkCom.id;
    switch (l) {
        case 1: [controller->window makeKeyAndOrderFront:NSApp];  
            break;
        case 2: [controller->searchWindow makeKeyAndOrderFront:nil];
            break;
        case 3: [controller->entryWindow makeKeyAndOrderFront:nil];
            break;  
    }
    return noErr;
}

- (void)awakeFromNib
{
    //Register the Hotkeys
    EventHotKeyRef gMyHotKeyRef;
    EventHotKeyID gMyHotKeyID;
    EventTypeSpec eventType;
    eventType.eventClass=kEventClassKeyboard;
    eventType.eventKind=kEventHotKeyPressed;


    InstallApplicationEventHandler(&MyHotKeyHandler,1,&eventType,(void *)self,NULL);

    gMyHotKeyID.signature='htk1';
    gMyHotKeyID.id=1;
    if([[NSUserDefaults standardUserDefaults] integerForKey:@"hotkeyCodeMain"]!=-999) {
        RegisterEventHotKey([[NSUserDefaults standardUserDefaults] integerForKey:@"hotkeyCodeMain"], [[NSUserDefaults standardUserDefaults] integerForKey:@"hotkeyModifiersMain"], gMyHotKeyID, GetApplicationEventTarget(), 0, &gMyHotKeyRef);
    }

    gMyHotKeyID.signature='htk2';
    gMyHotKeyID.id=2;
    if([[NSUserDefaults standardUserDefaults] integerForKey:@"hotkeyCodeSearch"]!=-999) {
        RegisterEventHotKey([[NSUserDefaults standardUserDefaults] integerForKey:@"hotkeyCodeSearch"], [[NSUserDefaults standardUserDefaults] integerForKey:@"hotkeyModifiersSearch"], gMyHotKeyID, GetApplicationEventTarget(), 0, &gMyHotKeyRef);
    }

    gMyHotKeyID.signature='htk3';
    gMyHotKeyID.id=3;
    if([[NSUserDefaults standardUserDefaults] integerForKey:@"hotkeyCodeEntry"]!=-999) {
        RegisterEventHotKey([[NSUserDefaults standardUserDefaults] integerForKey:@"hotkeyCodeEntry"], [[NSUserDefaults standardUserDefaults] integerForKey:@"hotkeyModifiersEntry"], gMyHotKeyID, GetApplicationEventTarget(), 0, &gMyHotKeyRef);
    }

}

在NIB中，我還將文本字段連接到NSDefaultsController。

Answer 1

通常，這意味着您正在嘗試訪問某個對象的名為hotKeyDisplayEntry的鍵，但是該對象沒有此類鍵。 您可能輸入了錯誤或輕微的邏輯錯誤。

Answer 2

您（或某些代碼）似乎在類上使用鍵值編碼。 我假設某個地方有一個hotKeyDisplayEntry ivar，也許是在筆尖和連接中定義的，但在您的課程中卻沒有？

另請閱讀：

可可中的鍵值編碼（apple.com）

如果不是以上方法，則可能是在ivar上指定了一個Observer或正在使用對象序列化，並且實際上沒有用於它的訪問器方法，因此引發了異常。 要么，要么您需要擴展您為我提供幫助的實際工作！