ios – UIPageViewController没有显示点

这是我正在使用的代码：

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{ 
    if(viewController == oneViewController) {
        self.navigationController.navigationItem.title=@"Options";
        return twoViewController;
    }
    else
    {
        self.navigationController.navigationItem.title=@"All schedule";
        return oneViewController;
    }
} 

- (NSInteger)presentationCountForPageViewController:(UIPageViewController *)pageViewController
{
    return 2;
}