参考资料: http://www.iphonedevbook.com/forum/iphone-development-questions/1450-class-not-key-value-coding-compliant.html
UITabBarController中加入DatePicker控件,连接好IBOutlet,一运行就出现如下的崩溃:
2009-06-10 13:12:58.899 Pickers[3878:20b] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<UIViewController 0xd191b0> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key datePicker.'
原来要给每一个子的标签页赋予特化的子类.坑爹的书!
For each tab in the tab tab, the class identity must be set the the name of the corresponding controller class.