避免用戶使用UIPageViewController滾動到索引-1和2

Question

我有一個具有2個VC（索引0和1）的UIPageViewController，我想避免用戶在第一個視圖（索引0）上滾動到右側，並且滾動到第二個視圖（索引1）的左側。

有沒有人可以告訴我我該怎麼做？

謝謝！

Answer 1

嘗試這些數據源的方法：

@SWIFT版本

public func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? { 
    var index = viewControllers.indexOf(viewController) 
    if index == 0 || index == NSNotFound { 
     return nil 
    } 

    index-- 
    return viewControllerAtIndex(index) 
} 

public func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? { 
    var index = viewControllers.indexOf(viewController) 
    if index == NSNotFound { 
     return nil 
    } 

    index++ 
    if index == viewControllers?.count { 
     return nil 
    } 

    return viewControllerAtIndex(index) 
} 

@OBJC版本

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController { 
    NSInteger index = [viewControllerArray indexOfObject:viewController]; 

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

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

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController { 
    NSInteger index = [viewControllerArray indexOfObject:viewController]; 

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

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

Answer 2

可以使用UIPageViewcontroller的指數值來實現這一目標。但是這很痛苦......讓你檢查一下。