ios - 在 UIPageViewController 中手动切换 View 导致异常

Question

我有一个 UIPageViewController，它显示两个 UIViewController 并允许用户在两​​者之间滑动。我实现了一个按钮，允许用户在两​​者之间手动切换。执行它的代码如下:

[self setViewControllers:@[[self.storyboard instantiateViewControllerWithIdentifier:@"PlayersViewController"]] direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:^(BOOL completion){}];

不幸的是，每次我按下按钮，我都会得到一个异常:

* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* -[__NSPlaceholderArray initWithObjects:count:]: attempt to insert nil object from objects[0]'

我从扩展 UIPageViewControllerDelegate 的自定义类中调用该方法。

如有任何帮助，我们将不胜感激!

**编辑:

以下是我的自定义类的相关部分:

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.dataSource = self;
    gvc = [[GamesViewController alloc] init];
    pvc = [[PlayersViewController alloc] init];
    [self setViewControllers:@[[self.storyboard instantiateViewControllerWithIdentifier:@"GamesViewController"]] direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];
}

- (void) slidepage
{
    [self setViewControllers:@[[self.storyboard instantiateViewControllerWithIdentifier:@"PlayersViewController"]] direction:UIPageViewControllerNavigationDirectionReverse animated:NO completion:^(BOOL completion){NSLog(@"hihi");}];
}

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
{
    if ([viewController isKindOfClass:[GamesViewController class]])
        return nil;

    return [self.storyboard instantiateViewControllerWithIdentifier:@"GamesViewController"];
}

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{
    if ([viewController isKindOfClass:[PlayersViewController class]])
        return nil;

    return [self.storyboard instantiateViewControllerWithIdentifier:@"PlayersViewController"];
}

Answer 1

好像是

[self.storyboard instantiateViewControllerWithIdentifier:@"PlayersViewController"]

返回 nil。这意味着要么 self.storyboard 为 nil，要么 Storyboard找不到给定标识符的 View Controller 。