如何检测UIPageViewController到达最后一页

Question

如何检测最后一页已pageViewController被调用，如果我想在最后一页上添加手势识别器并转发到我的应用程序主页，有没有办法做到这一点？

这是我的基本pageViewController片段，在我的UIPageViewController viewDidLoad

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Create the data model
    _pageImages = @[@"intro_1@2x.png", @"intro_2@2x.png", @"intro_3@2x.png", @"intro_4@2x.png"];

    // Create page view controller
    self.pageViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"RKYGuide"];
    self.pageViewController.dataSource = self;

    RKYGuideContentViewController *startingViewController = [self viewControllerAtIndex:0];
    NSArray *viewControllers = @[startingViewController];
    [self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];

    [self addChildViewController:_pageViewController];
    [self.view addSubview:_pageViewController.view];
    [self.pageViewController didMoveToParentViewController:self];
}

此外，还实现了两个页面视图控制器数据源方法

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
{
    NSUInteger index = ((RKYGuideContentViewController*) viewController).pageIndex;

    if ((index == 0) || (index == NSNotFound)) {
        return nil;
    }

    index--;
    return [self viewControllerAtIndex:index];
}

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{
    NSUInteger index = ((RKYGuideContentViewController*) viewController).pageIndex;

    if (index == NSNotFound) {
        return nil;
    }

    index++;

    if (index == [self.pageImages count]) {
        // adding gesture
        pageViewController.view.userInteractionEnabled = YES;
        pageViewController.view.contentMode = UIViewContentModeScaleAspectFit;
        UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc]
                                             initWithTarget:self
                                             action:@selector(startAction)];
        [singleTap setNumberOfTapsRequired:1];
        pageViewController.view.userInteractionEnabled = YES;
        [pageViewController.view addGestureRecognizer:singleTap];

        return nil;
    }

    NSLog(@"index: %u", index);

    return [self viewControllerAtIndex:index];
}

它工作正常，但我不知道在到达最后一页并导致我的主页时在哪里添加手势识别器。

编辑：我确实在 viewControllerAfterViewController 中添加了手势识别器，但它不起作用，没有响应。

Answer 1

您已经检查了最后一页是否已到达

if (index == [self.pageImages count]) {        
    return nil;
}

因此，如果您想做一些特殊的事情，则必须在返回之前将代码插入此块中。