Swift 4 在计时器的帮助下在页面视图控制器中自动滑动

Swift 4 auto slide in page view controller with help of timer

我正在尝试使用 swift 4page view controller 中创建 auto sliding。在这里,我尝试了下面的代码,但我得到了结果,它首先重复 index 图像。我需要知道,如何实现下一个索引的移动?

// Image array
var name = ["one.png","two.png","three.png","four.png"]

// Timer in viewdidload()
tTime = Timer.scheduledTimer(timeInterval: 4, target: self, selector: #selector(changeSlide), userInfo: nil, repeats: true)

// Timer function call (The problem is here...)
@objc func changeSlide() { 
        let pageContentViewController = self.viewControllerAtIndex(index: 0)
        self.pageViewController.setViewControllers([pageContentViewController!], direction: UIPageViewControllerNavigationDirection.forward, animated: true, completion: nil)
} 
    // Image array
    var name = ["one.png","two.png","three.png","four.png"]
    var currentIndex = -1

    // Timer in viewdidload()
    tTime = Timer.scheduledTimer(timeInterval: 4, target: self, selector: #selector(changeSlide), userInfo: nil, repeats: true)


    // Timer function call
    @objc func changeSlide() 
   {
    currentIndex = (currentIndex == name.count - 1) ? 0 : currentIndex + 1

    let pageContentViewController = self.viewControllerAtIndex(index: currentIndex)
    self.pageViewController.setViewControllers([pageContentViewController!], direction: UIPageViewControllerNavigationDirection.forward, animated: true, completion: nil)
}