class_respondsToSelector  判断某个类是否有某个实例方法，有则返回YES，否则返回NO ~~~ /** * Returns a Boolean value that indicates whether instances of a class respond to a particular selector. * * @param cls The class you want to inspect. * @param sel A selector. * * @return \c YES if instances of the class respond to the selector, otherwise \c NO. * * @note You should usually use \c NSObject's \c respondsToSelector: or \c instancesRespondToSelector: * methods instead of this function. */ OBJC_EXPORT BOOL class_respondsToSelector(Class cls, SEL sel) __OSX_AVAILABLE_STARTING(__MAC_10_5, __IPHONE_2_0); ~~~ 测试： ~~~ - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. //其中printDZL是Person类的实例方法，printDZ是Person类的类方法 Person * p1 = [[Person alloc] init]; BOOL isOrNot = class_respondsToSelector([p1 class], @selector(printDZL)); BOOL isOrNot2 = class_respondsToSelector([Person class], @selector(printDZ)); NSLog(@"%i--%i", isOrNot, isOrNot2); } ~~~ 输出： ~~~ 2015-11-04 13:53:33.019 02-runtime[3053:76771] 1--0 ~~~