下级界面找到上级viewcontroller

- (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;

}