在 UIScrollView 上创建一个循环

Question

我可以在视图上来回滚动，但我不能循环视图，因此当我在 ViewController3 上时它会向后滚动并在 ViewController1 上向前滚动以创建循环。我该怎么做？

下面的代码是我到目前为止所做的。

import UIKit

class ViewController: UIViewController {

@IBOutlet weak var scrollView: UIScrollView!

override func viewDidLoad() {
    super.viewDidLoad()

    let vc0 = ViewController0(nibName: "ViewController0", bundle: nil)

    var frame0 = vc0.view.frame
    frame0.origin.x = self.view.frame.size.width
    vc0.view.frame = frame0

    self.addChildViewController(vc0)
    self.scrollView.addSubview(vc0.view)
    vc0.didMove(toParentViewController: self)

    let vc1 = ViewController1(nibName: "ViewController1", bundle: nil)

    var frame1 = vc1.view.frame
    frame1.origin.x = self.view.frame.size.width
    vc1.view.frame = frame1

    self.addChildViewController(vc1)
    self.scrollView.addSubview(vc1.view)
    vc1.didMove(toParentViewController: self)

    let vc2 = ViewController2(nibName: "ViewController2", bundle: nil)

    var frame2 = vc2.view.frame
    frame2.origin.x = self.view.frame.size.width * 2
    vc2.view.frame = frame2

    self.addChildViewController(vc2)
    self.scrollView.addSubview(vc2.view)
    vc2.didMove(toParentViewController: self)

    let vc3 = ViewController3(nibName: "ViewController3", bundle: nil)

    var frame3 = vc3.view.frame
    frame3.origin.x = self.view.frame.size.width * 3
    vc1.view.frame = frame3

    self.addChildViewController(vc3)
    self.scrollView.addSubview(vc3.view)
    vc3.didMove(toParentViewController: self)

    self.scrollView.contentSize = CGSize(width: Double(self.view.frame.size.width * 4), height: Double(self.view.frame.size.height - 66))

}



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

}

Answer 1

实际上，我建议您完全放弃使用 UIScrollView 并改用 UIPageViewController。它使这种事情变得微不足道，因为您一次只需要提供一个页面，并且进行您描述的那种无限或循环滚动很容易，因为您每次只需在循环系列中继续提供“下一个”视图控制器被要求。另外，它会为您处理整个亲子舞蹈（并不是说您这样做有什么问题）。