JSONKit有两个warning。// array->isa = _JKArrayClass;// warning
object_setClass(array, _JKArrayClass); // 更正
dictionary->isa = _JKDictionaryClass;// warning
object_setClass(dictionary, _JKDictionaryClass);// 更正
原因isa已经被废弃了，所以请调用object_setClass()和object_getClass()