Question

我一直在努力让UIPageViewController工作很长一段时间，而且缺乏结果开始让我疯狂......

以下代码是部分教程（我也没有开始工作）和部分我。现在我正在尝试让每个viewControllers查看一个标签，这样我就可以确保它在添加内容之前有效。

- (void)viewDidLoad
{
[super viewDidLoad];

vcArray = [self createViewControllers:1];
NSLog(@"TEST1");


self.pageController = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal options:nil];
self.pageController.delegate = self;
self.pageController.dataSource = self;
NSLog(@"TEST2 %@", vcArray);
[self.pageController setViewControllers:vcArray direction:UIPageViewControllerNavigationDirectionForward animated:YES completion:nil];
[[pageController view] setFrame:[[self view] bounds]];
NSLog(@"TEST3");
[self addChildViewController:self.pageController];
[[self view] addSubview:[self.pageController view]];
[pageController didMoveToParentViewController:self];
NSLog(@"TEST4");

}

- (NSArray *) createViewControllers:(NSInteger)ammount{
NSMutableArray *array = [NSMutableArray new];
for (NSInteger i = 0; i <= ammount; i++) {
    PageContentViewController *pageContentViewController = [PageContentViewController new];
    UILabel *label = [UILabel new];
    label.text = @"STRING";
    pageContentViewController.view = label;
    [array addObject:pageContentViewController];
}
return array;
}

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
{
NSUInteger index = [self indexOfViewController:
                    (PageContentViewController *)viewController];
if ((index == 0) || (index == NSNotFound)) {
    return nil;
}

index--;
return [vcArray objectAtIndex:index];
}

- (UIViewController *)pageViewController:
(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{
NSUInteger index = [self indexOfViewController:
                    (PageContentViewController *)viewController];
if (index == NSNotFound) {
    return nil;
}

index++;
if (index == [vcArray count]) {
    return nil;
}
return [vcArray objectAtIndex:index];
}

- (NSUInteger)indexOfViewController:(PageContentViewController *)viewController
{
return [vcArray indexOfObject:viewController.dataObject];
}

你能看到我错过的东西吗？我一直在经历太多的教程和stackoverflow问题，这让我更加困惑......

提前致谢，汤姆

Answer 1

一般提示：

请勿使用[PageContentViewController new]，请使用[[PageContentViewController alloc] initWithNibName:nil bundle:nil]。请勿使用[UILabel new]，请使用[[UILabel alloc] initWithFrame:CGZeroRect]。

逐步完成代码。检查应该是nil对象的内容。 Objective-C会默默地允许事物nil，即使你在它们上面调用方法！

无法让UIPageViewController工作

1 个答案: