iphone - UIPageViewController : get the currentPage

Question

过去几天我一直在为这个问题苦苦挣扎，在所有这些杂耍之后，我发现我所需要的只是数据源方法中的当前索引，以使用当前可见页码进行更新

我有这个 UIPageViewController 数据源方法，我需要使用当前索引来获取委托(delegate)方法的当前可见页面 previousViewControllers transitionCompleted:(BOOL)completed

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController
   viewControllerAfterViewController:(UIViewController *)viewController { 
    NSString *path = [[NSBundle mainBundle] pathForResource:@"pages" ofType:@"pdf"];

    NSURL *pdfurl = [NSURL fileURLWithPath:path];
    PDFDocument = CGPDFDocumentCreateWithURL((__bridge CFURLRef)pdfurl);

    contentViewController = [[ContentViewController alloc] initWithPDFAtPath:path];

    currentIndex = [modelArray indexOfObject:[(ContentViewController *)viewController page]];

    if (currentIndex == totalPages - 1) {  
        return nil;
    }

    contentViewController.page = [modelArray objectAtIndex:currentIndex + 1];

    return contentViewController;
}

我很困惑如何将当前索引语句从数据源方法写入委托(delegate)方法以更新当前可见页面。

- (void)pageViewController:(UIPageViewController *)pageViewController didFinishAnimating:(BOOL)finished previousViewControllers:(NSArray *)previousViewControllers transitionCompleted:(BOOL)completed{

    if (!completed)
    {
        return;
    }

    //currentIndex = [[self.pageViewController.viewController lastObject]];  
    currentIndex = [self indexOfObject:contentViewController];

    [self displaycurrentIndex:currentIndex];
    //self.pageControl.currentPage = currentIndex;
}

我该如何纠正这个问题？

Answer 1

看起来你应该能够通过以下方式获取当前索引:

ContentViewController *viewController = [self.pageViewController.viewControllers lastObject];
currentIndex = [modelArray indexOfObject:[viewController page]];