Swift - 单击按钮更改 UIPageViewController 视图

Question

我正在使用UIPageViewController，我的目的是在点击UIButton 时切换其UIViewController 之一的当前视图。我已经用谷歌搜索了我的问题并找到了一些类似的主题，但我无法确定答案。

例如，我的第二个UIViewController vc2 中的按钮应将视图更改为vc3。

RootPageViewController

import UIKit

class RootPageViewController: UIPageViewController, UIPageViewControllerDataSource {

    lazy var viewControllerList:[UIViewController] = {

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

        let vc1 = sb.instantiateViewController(withIdentifier: "timelineView")
        let vc2 = sb.instantiateViewController(withIdentifier: "mainView")
        let vc3 = sb.instantiateViewController(withIdentifier: "addView")

        return [vc1, vc2, vc3]
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        self.dataSource = self

        let secondViewController = viewControllerList[1]
        self.setViewControllers([secondViewController], direction: .forward, animated: false, completion: nil)

    }

    func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
        guard let vcIndex = viewControllerList.firstIndex(of: viewController) else { return nil }

        let previousIndex = vcIndex - 1
        guard previousIndex >= 0 else { return nil }

        guard viewControllerList.count > previousIndex else { return nil }

        return viewControllerList[previousIndex]
    }

    func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
        guard let vcIndex = viewControllerList.firstIndex(of: viewController) else { return nil }

        let nextIndex = vcIndex + 1

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

        guard viewControllerList.count > nextIndex else { return nil }

        return viewControllerList[nextIndex]
    }

}

第二个 ViewController 内的按钮

@IBAction func addData(_ sender: Any) {


    }

Answer 1

在RootPageViewController 的viewDidLoad 中，将第二个视图控制器按钮的目标添加到self，并将addData 方法添加到RootPageViewController。您可以使用setViewControllers 并在该方法中移动到最后一个视图控制器

override func viewDidLoad() {
    super.viewDidLoad()

    self.dataSource = self
    if let secondViewController = viewControllerList[1] as? SecondViewController {
        self.setViewControllers([secondViewController], direction: .forward, animated: false, completion: nil)
        secondViewController.button.action = #selector(addData(_:))
    }
}
@IBAction func addData(_ sender: Any) {
    if let thirdViewController = viewControllerList.last {
        self.setViewControllers([thirdViewController], direction: .forward, animated: false, completion: nil)
    }
}

或

在 MainViewControlle 中保留 addData 方法并像这样向它添加协议

protocol MainVCDelegate {
    func buttonPlusTapped()
}
class MainViewController: UIViewController {

    @IBOutlet var buttonPlus: UIBarButtonItem!

    var delegate: MainVCDelegate?
    @IBAction func addData(_ sender: Any) {
        delegate?.buttonPlusTapped()
    }
}

在 RootPageViewController 中确认这个委托并添加委托方法

class RootPageViewController: UIPageViewController, UIPageViewControllerDataSource, MainVCDelegate {

    func buttonPlusTapped() {
        if let thidViewController = viewControllerList.last {
            self.setViewControllers([thidViewController], direction: .forward, animated: false, completion: nil)
        }
    }

    lazy var viewControllerList:[UIViewController] = {

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

        let vc1 = sb.instantiateViewController(withIdentifier: "timelineView")
        let vc2 = sb.instantiateViewController(withIdentifier: "mainView") as! MainViewController
        vc2.delegate = self
        let vc3 = sb.instantiateViewController(withIdentifier: "addView")
        return [vc1, vc2, vc3]
    }()
}