swift - 如何通过 PageViewController 将 viewController 的数据传递给 pageViewController 的第二个 ViewController

Question

我是新手，我试图通过管理 3 个 viewController 的 pageViewController 为 viewController 传递一些变量，并在 3 个 Controller 中使用这些变量，有人可以帮助我吗？

这是我在 swift 上的代码...

我用这个发送我的变量:

public var lenguaje = ""
public var username = ""
public var indice = ""
public var password = ""

  if segue.identifier == "loginPage" {
        let destino = segue.destination as! RootPageViewController
        destino.lenguaje=lenguaje
        destino.username = self.txtUsuario.text!
        destino.indice = indice
        destino.password = self.txtPassword.text!

当我这样做时，调用 Web 服务的 viewController 需要其中两个变量，例如参数...所以当 View Controller 出现时，它不起作用...

这是我的 RootPageViewController 类

class RootPageViewController: UIPageViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate {

public var lenguaje = ""
public var username = ""
public var indice = ""
public var password = ""

lazy var viewControllerList: [UIViewController] = {

    let sb = UIStoryboard(name: "Main" , bundle: nil)

    let vc1 = sb.instantiateViewController(withIdentifier: "principal1") //this is well done
    let vc2 = sb.instantiateViewController(withIdentifier: "Principal2")
    let vc3 = sb.instantiateViewController(withIdentifier: "Principal3")

    return [vc1,vc2,vc3]


}()

func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {

    guard let vcIndex = viewControllerList.index(of: viewController) else { return nil}

    let previo = vcIndex - 1

    guard previo >= 0 else {return nil}

    guard viewControllerList.count > previo else {return nil}

    return viewControllerList[previo]

}

func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {

    guard let vcIndex  = viewControllerList.index(of: viewController) else {return nil}

    let next = vcIndex + 1

    guard viewControllerList.count != next else {return nil}

    guard viewControllerList.count > next else {return nil}

    return viewControllerList[next]
}


override func viewDidLoad() {
    super.viewDidLoad()

    self.dataSource = self

    if let firstViewController = viewControllerList.first{
        self.setViewControllers([firstViewController], direction: .forward, animated: true, completion: nil)
    }



    // Do any additional setup after loading the view.
}



}

变量直接传递给这个类，我打印它们并在我进入PageViewController时显示它们，但是我如何将它们从这个传递给PageViewController的第一个viewController(principal1)以便调用webservice有用吗？

Answer 1

有几种方法。

最简单的方法是在实例化 vc1、vc2、vc3 时，将变量传递给 View Controller 。

但是，我会根据您的用例构建类。例如，有一个保存变量的数据提供者，这样您的整个页面 VC 流(包括 vc1、vc2、vc3)就可以对数据进行必要的访问。您可以通过子类、委托(delegate)来实现。