如何使用UIPageViewController还显示上一个和下一个视图的一部分

Question

我使用了这个惊人的教程如何在Swift中使用UIPageViewController来理解和实现我的应用程序中的UIPageViewController.

我已成功完成集成,但我现在需要修改一点行为.

我不想一次只查看一个彩色视图,而是查看前一个视图的25%和下一个视图的25%.

我想我必须使用这个方法传递3个viewcontrollers:

func setViewControllers(_ viewControllers: [UIViewController]?, 
          direction: UIPageViewControllerNavigationDirection, 
           animated: Bool, 
         completion: ((Bool) -> Void)? = nil)

......但我不知道该怎么做

Answer 1

当您使用滚动视图创建 UIPageviewcontroller 时，这很容易实现。是的，您可以使用 UIScrollView 像 pageviewcontroller 一样显示它。现在显示矩形（在您的情况下为当前屏幕 + 第二个屏幕的 25%）就在您手中。

下面是代码。

    import UIKit

class ViewController: UIViewController,UIScrollViewDelegate {

    let scrollView = UIScrollView(frame: CGRectMake(0, 0, 320, 300))
    var colors:[UIColor] = [UIColor.redColor(), UIColor.blueColor(), UIColor.greenColor(), UIColor.yellowColor()]
    var frame: CGRect = CGRectMake(0, 0, 0, 0)
    var pageControl : UIPageControl = UIPageControl(frame: CGRectMake(50, 300, 200, 50))


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
         configurePageControl()

        scrollView.delegate = self
        self.view.addSubview(scrollView)
        for index in 0..<4 {

            frame.origin.x = self.scrollView.frame.size.width * CGFloat(index)
            frame.size = self.scrollView.frame.size
            self.scrollView.pagingEnabled = true

            var subView = UIView(frame: frame)
            subView.backgroundColor = colors[index]
            self.scrollView .addSubview(subView)
        }

        self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * 4, self.scrollView.frame.size.height)
        pageControl.addTarget(self, action: Selector("changePage:"), forControlEvents: UIControlEvents.ValueChanged)

           }

    func configurePageControl() {
        // The total number of pages that are available is based on how many available colors we have.
        self.pageControl.numberOfPages = colors.count
        self.pageControl.currentPage = 0
        self.pageControl.tintColor = UIColor.redColor()
        self.pageControl.pageIndicatorTintColor = UIColor.blackColor()
        self.pageControl.currentPageIndicatorTintColor = UIColor.greenColor()     
        self.view.addSubview(pageControl)

         }

    // MARK : TO CHANGE WHILE CLICKING ON PAGE CONTROL
    func changePage(sender: AnyObject) -> () {
        let x = CGFloat(pageControl.currentPage) * scrollView.frame.size.width
        scrollView.setContentOffset(CGPointMake(x, 0), animated: true)
    }

    func scrollViewDidEndDecelerating(scrollView: UIScrollView) {

        let pageNumber = round(scrollView.contentOffset.x / scrollView.frame.size.width)
        pageControl.currentPage = Int(pageNumber)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}