我有2个UIViewController
。
一个UIViewController
的视图带有许多按钮,并且高度为+2000点。
另一个UIViewController
具有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)
}
}
并且虽然拇指
UIViewController
已加载到UIScrollView
,但是大小错误并且无法滚动。任何帮助表示赞赏
最佳答案
在运行时加载视图时,调整视图的大小会遇到问题。几个选项...
// 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)
}
}
我建议在
setupC()
中使用该方法,它使用自动布局约束,并且没有硬编码的大小值。使规划不同的设备尺寸(以及将来在其他视图/应用/作业/等中使用)的规划变得更加容易。