问题：isMemberOfClass 和 isKindOfCla

isMemberOfClass 和isKindOfClass 都是NSObject的比较Class的方法。但：

• isKindOfClass:确定一个对象是否是一个类的成员,或者是派生自该类的成员.
• isMemberOfClass:确定一个对象是否是当前类的成员。

if ([scrollView isKindOfClass:[UIView class]]) {
    NSLog(@"scrollView is isKindOfClass UIView");
}

if ([scrollView isKindOfClass:[UIScrollView class]]) {
    NSLog(@"scrollView is isKindOfClass UIScrollView");
}

if ([scrollView isMemberOfClass:[UIView class]]) {
    NSLog(@"scrollView is isMemberOfClass UIView");
}

if ([scrollView isMemberOfClass:[UIScrollView class]]) {
    NSLog(@"scrollView isMemberOfClass UIScrollView");
}
输出结果：
scrollView is isKindOfClass UIView
scrollView is isKindOfClass UIScrollView
(无)
scrollView isMemberOfClass UIScrollView