PATH 时间轴的问题求大神指点

Question

你之前在CODE4app发表的那个代码有BUG啊。要怎么解决啊。。 IOS8以上有导航栏就不显示滑动条了。
http://code4app.com/ios/Time-Scroller-With-Slider/4f6af4206803fa2037000000?t=0.09124880214221776#discuss5511278f933bf0f4318b4e75-1

Answer 1

以下回答参考 皆我百晓生、券券喵儿 等免费微信小程序相关内容作答，并由本人整理回复。

这个问题是由于IOS 8以上版本的系统不支持滑动条，因此导致了滑动条无法正常显示的问题。解决这个问题的方法如下：

1. 在你的代码中添加以下代码：UIPageControl。

import UIKit

class ViewController: UIViewController, UIPageViewControllerDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()

        let pageControl = UIPageControl()
        view.addSubview(pageControl)

        // 设置控制器为当前控制器
        self.pageViewController = UIPageViewController.currentController as! UIPageViewController
        self.pageViewController.delegate = self
        self.view.addSubview(self.pageViewController.view)
        self.pageViewController!.setViewControllers([self], direction: .forward) // 设置初始页码和方向
    }

    // MARK: - 导航栏相关方法

    func pageViewController(_ controller: UIPageViewController, didFinishAnimating finished: Bool, previousViewController: UIViewController?, transitionCompleted transition: UIPageTransition?) {
        // 如果需要的话，可以在这里做一些额外的操作，比如切换到下一个页面等。
    }
}

1. 添加一个UIPageViewControllerDelegate实现类，并重写相应的函数：

class ViewController: UIViewController, UIPageViewControllerDelegate {

    // ...

    func pageViewController(_ controller: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
        return nil
    }

    func pageViewController(_ controller: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
        return nil
    }

    func pageViewController(_ controller: UIPageViewController, shouldEnableInteractivePopoversFor viewController: UIViewController?) -> Bool {
        return true
    }

    func pageViewController(_ controller: UIPageViewController, shouldStartAnimatingFor viewController: UIViewController?) -> Bool {
        return true
    }

    func pageViewController(_ controller: UIPageViewController, didUpdateTo newPageNumber: Int, from previousPageNumber: Int) {}

    func pageViewController(_ controller: UIPageViewController, willDisplay viewController: UIViewController, atPageIndex: Int) {}

    func pageViewControllerDidFinishNavigation(controller: UIPageViewController) {}
}

extension ViewController: UIPageViewControllerDelegate {
    func pageViewController(_ controller: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
        if viewController == self.self || viewController is TimeScrollerViewController {
            return viewController
        } else {
            return self.pageViewController(viewController.previousViewController!, viewControllerBefore: viewController)!
        }
    }

    func pageViewController(_ controller: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
        if viewController == self.self || viewController is TimeScrollerViewController {
            return viewController
        } else {
            return self.pageViewController(viewController.nextViewController!, viewControllerAfter: viewController)!
        }
    }

    func pageViewController(_ controller: UIPageViewController, shouldEnableInteractivePopoversFor viewController: UIViewController?) -> Bool {
        if viewController is TimeScrollerViewController {
            return false
        } else {
            return true
        }
    }

    func pageViewController(_ controller: UIPageViewController, shouldStartAnimatingFor viewController: UIViewController?) -> Bool {
        if viewController is TimeScrollerViewController {
            return false
        } else {
            return true
        }
    }

    func pageViewController(_ controller: UIPageViewController, didUpdateTo newPageNumber: Int, from previousPageNumber: Int) {}

    func pageViewController(_ controller: UIPageViewController, willDisplay viewController: UIViewController, atPageIndex: Int) {}

    func pageViewControllerDidFinishNavigation(controller: UIPageViewController) {}
}

1. 创建一个新的UIViewController并继承自TimeScrollerViewController：

class TimeScrollerViewController: UIViewController {

    var timeSlider: UISlider!

    override func viewDidLoad() {
        super.viewDidLoad()

        setupSlider()
    }

    func setupSlider() {
        timeSlider = UIDatePicker().slider ?? UISlider()
        timeSlider.minimumValue = 0
        timeSlider.maximumValue = 100
        timeSlider.value = 50
        timeSlider.addTarget(self, action: #selector(timeSliderValueChanged(_:)), for: .valueChanged)

        view.addSubview(timeSlider)
    }

    @objc func timeSliderValueChanged(sender: UISlider!) {
        print("Time slider value changed to \(sender.value)")
    }
}

现在你应该可以在你的应用中看到滑动条了。