为什么会出现错误“类型ViewController不符合协议UIPageViewControllerDataSource”？

Question

I am looking to set up a VC that handles my UIPageViewControllerDataSource but for whatever reason I am getting this error. Is there another protocol I need to include. My code:

class ViewController: UIViewController, UIPageViewControllerDelegate, UIPageViewControllerDataSource

Thanks!

Answer 1

Adding the protocol definition for your custom class is not enough. You have to provide at least the two required functions of the UIPageViewControllerDataSource protocol:

func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? 

func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController?

Take a close look at the methods you can implement within your class in the UIPageViewControllerDataSource Protocol Reference documentation.

Answer 2

You have to implement the following methods:

• pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController?

• pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController?