获取当前视图UIView的主控件UIViewController

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