在 UIScrollView Swift3 中加载 UIViewController

Question

我有 2 个 UIViewController。一个 UIViewController 有一个有很多按钮的视图并且是 +2000 点高。另一个 UIViewController 有一个 UIScrollView.

这是我的代码：

import UIKit

 class ViewController: UIViewController {

@IBOutlet weak var scrollView: UIScrollView!


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


    scrollView.contentSize = CGSize(width: 375, height: 2884)

    DispatchQueue.main.async {
        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let thumb_vc = storyboard.instantiateViewController(withIdentifier: "thumb") as! ThumbsViewController
        //self.present(vc, animated: true, completion: nil)

    self.addChildViewController(thumb_vc)
    self.scrollView.addSubview(thumb_vc.view)
   }
 }

虽然缩略图 UIViewController 加载到 UIScrollView，但大小不对，无法滚动。

感谢任何帮助

Answer 1

当您可以使用自动布局轻松地将 View 嵌入滚动视图时，为什么要为 ScrollView 提供静态高度。你可以参考这个 link, https://www.natashatherobot.com/ios-autolayout-scrollview/

Answer 2

您运行遇到了一个问题，即在运行时加载时会调整视图的大小。情侣选项...

// NOT USING constraints / auto-layout
func setupA() -> Void {

    scrollView.contentSize = CGSize(width: 375, height: 2884)

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

    if let vc = storyboard.instantiateViewController(withIdentifier: "thumb") as? ThumbsViewController {

        // add the child VC
        self.addChildViewController(vc)

        // don't let "thumbs" view auto-resize
        vc.view.autoresizingMask = []

        // set "thumbs" view frame size to scroll view content size
        vc.view.frame = CGRect(origin: CGPoint.zero, size: scrollView.contentSize)

        // add "thumbs" view to the scroll view
        self.scrollView.addSubview(vc.view)

        // finish child VC process
        vc.didMove(toParentViewController: self)
    }

}

// USING constraints / auto-layout, with hard-coded sizing
func setupB() -> Void {

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

    if let vc = storyboard.instantiateViewController(withIdentifier: "thumb") as? ThumbsViewController {

        // add the child VC
        self.addChildViewController(vc)

        // add "thumbs" view to the scroll view
        self.scrollView.addSubview(vc.view)

        // disable auto-resizing mask
        vc.view.translatesAutoresizingMaskIntoConstraints = false

        // set constraints to both control the size of the "thumbs" view
        // as well as the contentSize of the scroll view

        // set width and height constraints for the "thumbs" view
        vc.view.widthAnchor.constraint(equalToConstant: 375).isActive = true
        vc.view.heightAnchor.constraint(equalToConstant: 2884).isActive = true

        // set leading, top, trailing, and bottom constraints to the scroll view
        vc.view.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor).isActive = true
        vc.view.topAnchor.constraint(equalTo: scrollView.topAnchor).isActive = true
        vc.view.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor).isActive = true
        vc.view.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor).isActive = true

        // finish child VC process
        vc.didMove(toParentViewController: self)
    }

}

// USING constraints / auto-layout, with sizing controlled by constraints set in IB for the "thumbs" view
func setupC() -> Void {

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

    if let vc = storyboard.instantiateViewController(withIdentifier: "althumb") as? ALThumbsViewController {

        // add the child VC
        self.addChildViewController(vc)

        // add "thumbs" view to the scroll view
        self.scrollView.addSubview(vc.view)

        // disable auto-resizing mask
        vc.view.translatesAutoresizingMaskIntoConstraints = false

        // the constraints set in Interface Builder for the elements in the "thumbs" view
        // will control its size

        // setting the "edge" constraints relative to the scroll view will control the contentSize

        // set leading, top, trailing, and bottom constraints to the scroll view
        vc.view.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor).isActive = true
        vc.view.topAnchor.constraint(equalTo: scrollView.topAnchor).isActive = true
        vc.view.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor).isActive = true
        vc.view.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor).isActive = true

        // finish child VC process
        vc.didMove(toParentViewController: self)
    }

}

我推荐 setupC() 中的方法，它使用没有硬编码大小值的自动布局约束。更容易规划不同的设备尺寸（以及未来在其他视图/应用程序/作业/等中的使用）。

Answer 3

您还必须指定 child 的框架。此外，无需在 viewDidLoad 方法中将 UI 更改分派到主队列。并且在将视图添加为子视图后，您必须调用 child 视图控制器的 didMove(toParentViewController:) 方法。您可以阅读有关容器视图控制器及其 children here.

的更多信息

在 UIScrollView Swift3 中加载 UIViewController

Loading UIViewController inside an UIScrollView Swift3

ios

swift3

xcode8