基于子视图（标签）以编程方式创建具有大小的 UIView

Question

我有一个需要完全以编程方式创建 UIView 的场景。此视图显示为视频源的叠加层，它包含 2 个 UILabel 作为子视图。

这些标签可以有不同的宽度和高度，所以我不想为 UIView 或标签创建一个固定的框架。

我已经用程序约束完成了这个，没有问题，但问题是移动手机时视图出现故障，我正在使用的框架建议不要使用自动布局，因为这个确切的问题.

我当前的代码：

• 我创建视图

      func ar(_ arViewController: ARViewController, viewForAnnotation: ARAnnotation) -> ARAnnotationView {
              let annotationView = AnnotationView() //*this is the view, inherits from UIView
              annotationView.annotation = viewForAnnotation
              annotationView.delegate = self
  
              return annotationView
          }
  

• 以及实际的视图代码

  class AnnotationView: ARAnnotationView {
  
  
          var titleLabel: UILabel?
          var distanceLabel: UILabel!
          var delegate: AnnotationViewDelegate?
          override var annotation: ARAnnotation? {
              didSet {
                  loadUI()
              }
          }
  
          override func didMoveToSuperview() {
              super.didMoveToSuperview()
  
              setupUI()
          }
  
          private func setupUI() {
              layer.cornerRadius = 5
              layer.masksToBounds = true
              backgroundColor = .transparentWhite
          }
  
          private func loadUI() {
              titleLabel?.removeFromSuperview()
              distanceLabel?.removeFromSuperview()
  
              let label = UILabel()
              label.font = UIFont(name: "AvenirNext-Medium", size: 16.0) ?? UIFont.systemFont(ofSize: 14)
              label.numberOfLines = 2
              label.textColor = UIColor.white
              self.titleLabel = label
  
              distanceLabel = UILabel()
              distanceLabel.textColor = .cbPPGreen
              distanceLabel.font = UIFont(name: "AvenirNext-Medium", size: 14.0) ?? UIFont.systemFont(ofSize: 12)
              distanceLabel.textAlignment = .center
  
              self.translatesAutoresizingMaskIntoConstraints = false
              label.translatesAutoresizingMaskIntoConstraints = false
              distanceLabel.translatesAutoresizingMaskIntoConstraints = false
  
              self.addSubview(label)
              self.addSubview(distanceLabel)
  
              if self.constraints.isEmpty {
                  NSLayoutConstraint.activate([
                      NSLayoutConstraint(item: label, attribute: .left, relatedBy: .equal, toItem: self, attribute: .left, multiplier: 1, constant: 5),
                      NSLayoutConstraint(item: label, attribute: .right, relatedBy: .equal, toItem: self, attribute: .right, multiplier: 1, constant: -5),
                      NSLayoutConstraint(item: label, attribute: .top, relatedBy: .equal, toItem: self, attribute: .top, multiplier: 1, constant: 0),
                      NSLayoutConstraint(item: label, attribute: .bottom, relatedBy: .equal, toItem: distanceLabel, attribute: .top, multiplier: 1, constant: 0),
  
                      NSLayoutConstraint(item: distanceLabel, attribute: .left, relatedBy: .equal, toItem: self, attribute: .left, multiplier: 1, constant: 0),
                      NSLayoutConstraint(item: distanceLabel, attribute: .right, relatedBy: .equal, toItem: self, attribute: .right, multiplier: 1, constant: 0),
                      NSLayoutConstraint(item: distanceLabel, attribute: .bottom, relatedBy: .equal, toItem: self, attribute: .bottom, multiplier: 1, constant: 0),
                      NSLayoutConstraint(item: distanceLabel, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 15),
                      ])
      }
  
              if let annotation = annotation as? BikeStationAR {
                  titleLabel?.text = annotation.address
                  distanceLabel?.text = String(format: "%.2f km", annotation.distanceFromUser / 1000)
              }
          }
  
          override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
              delegate?.didTouch(annotationView: self)
          }
      }        
  

所以我现在的问题是：如何在不使用自动布局的情况下实现相同的行为？

编辑：这是https://streamable.com/s/4zusq/dvbgnb行为的视频

编辑 2：解决方案基于 Mahgol Fa 的回答并使用堆栈视图或垂直定位，以便不为各个标签设置框架。所以最终的实现是

private func loadUI() {
        titleLabel?.removeFromSuperview()
        distanceLabel?.removeFromSuperview()

        let label = UILabel()
        label.font = titleViewFont
        label.numberOfLines = 0
        label.textColor = UIColor.white
        label.textAlignment = .center
        self.titleLabel = label

        distanceLabel = UILabel()
        distanceLabel.textColor = .cbPPGreen
        distanceLabel.font = subtitleViewFont
        distanceLabel.textAlignment = .center

        label.translatesAutoresizingMaskIntoConstraints = false
        distanceLabel.translatesAutoresizingMaskIntoConstraints = false

        if let annotation = annotation as? BikeStationAR {
            let title = annotation.address
            let subtitle = String(format: "%.2f km", annotation.distanceFromUser / 1000)

            let fontAttributeTitle = [NSAttributedString.Key.font: titleViewFont]
            let titleSize = title.size(withAttributes: fontAttributeTitle)

            let fontAttributeSubtitle = [NSAttributedString.Key.font: subtitleViewFont]
            let subtitleSize = annotation.address.size(withAttributes: fontAttributeSubtitle)

            titleLabel?.text = title
            distanceLabel?.text = subtitle

            let stackView = UIStackView(frame: CGRect(x: 0, y: 0, width: titleSize.width + 5, height: titleSize.height + subtitleSize.height + 5))
            stackView.axis = .vertical
            stackView.distribution = .fillProportionally
            stackView.alignment = .fill
            stackView.addArrangedSubview(titleLabel ?? UIView())
            stackView.addArrangedSubview(distanceLabel)

            frame = stackView.bounds
            addSubview(stackView)
        }
    }

Answer 1

这样你可以得到你的标签文本的宽度：

let fontAttributes1= [NSAttributedStringKey.font: your declared font in your code]
   let size1 = (“your string” as String).size(withAttributes: fontAttributes1)
let fontAttributes2= [NSAttributedStringKey.font: your declared font in your code]
   let size2 = (“your string” as String).size(withAttributes: fontAttributes2)

然后：

YourView.frame = CGRect( width: size1.width + size2.width + some spacing , height : ....)