UIPageViewController iOS 8的下一页按钮 - objC

Question

实际上我正在尝试使用PageViewController填充图库.我成功地在视图中添加了滚动图像但是,我在页面View Controller中使用了Next和Previous按钮,但是我使用了这行代码.

- (IBAction)previousButtonPressed:(id)sender {
    PageContentViewController *startingViewController = [self viewControllerAtIndex:0];
    NSArray *viewControllers = @[startingViewController];
    [self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionReverse animated:NO completion:nil];
}

- (IBAction)nextButtonPressed:(id)sender {
    PageContentViewController *startingViewController = [self viewControllerAtIndex:+1];
    NSArray *viewControllers = @[startingViewController];
    [self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];
    }

因为我在- (IBAction)nextButtonPressed:(id)发送者使用了viewControllerAtIndex:+1我只是在第一次点击按钮动作时才使按钮动作正常工作.提前致谢

Answer 1

检查此代码: -

- (void)changePage:(UIPageViewControllerNavigationDirection)direction {
    NSUInteger pageIndex = ((FooViewController *) [_pageViewController.viewControllers objectAtIndex:0]).pageIndex;
    if (direction == UIPageViewControllerNavigationDirectionForward){
        pageIndex++;
    }else {
        pageIndex--;
    }
    YourViewController *viewController = [self  viewControllerAtIndex:pageIndex];
    if (viewController == nil) {
        return;
    }
    [_pageViewController setViewControllers:@[viewController] direction:direction animated:YES completion:nil];
}

//上一个按钮

- (IBAction)previousButtonPressed:(id)sender {
    [self changePage:UIPageViewControllerNavigationDirectionReverse];
}

//下一个按钮

- (IBAction)nextButtonPressed:(id)sender {
    [self changePage:UIPageViewControllerNavigationDirectionForward];
}