获取view所属的controller

主要利用响应链

- (UIViewController *)getCurrentViewController {
    
    for (UIView *next = [self superview]; next; next =
         next.superview) {
        UIResponder* nextResponder = [next nextResponder];
        if ([nextResponder isKindOfClass:[UIViewController class]]) {
            return (UIViewController*)nextResponder;
        }
    }
    return nil;
}