Ios 使用UIView子类化自调整UILabel大小

我有一个草图，我试图通过编程实现这个概念

这是我的素描：

成就：

我的代码：

let luna = UIView()

let descStrWidth = messageDescription.stringWidth  // Using String Extension i made.
let descStrHeight = messageDescription.stringHeight // Using String Extension i made.

let titleStrHeight = messageTitle.stringHeight // ..
let titleStrWidth = messageTitle.stringWidth // .. 


let titleLabel = UILabel()
titleLabel.text = messageTitle
titleLabel.font = UIFont(name: "avenirnext-demibold", size: 13)
titleLabel.textColor = UIColor(hexString: "4A4A4A")
titleLabel.numberOfLines = 0 // whole idea of self-sizing 

let titleDesc = UILabel()
titleDesc.text = messageDescription
titleDesc.font = UIFont(name: "avenirnext-regular", size: 9)
titleDesc.textColor = UIColor(hexString: "4A4A4A")
titleDesc.numberOfLines = 0

// My mainView 

luna.frame = CGRect(x: 16, y: 40, width: screenWidth - 30, height: titleStrHeight + descStrHeight)
luna.center.x = luna.center.x
luna.backgroundColor = .white
luna.addShadow(radius: 11, opacity: 0.2) // Some Shadow
luna.layer.cornerRadius = 10

titleDesc.frame = CGRect(x: luna.frame.minX + 3, y: titleLabel.frame.maxY + titleStrHeight, width: luna.frame.width, height: descStrHeight)


titleLabel.frame = CGRect(x: luna.frame.minX + 3, y: 8, width: titleStrWidth, height: titleStrHeight)

luna.addSubview(titleLabel)
luna.addSubview(titleDesc)
self.view.addSubview(luna)

获取提供的字符串宽度和高度：

 extension String {
    var stringWidth: CGFloat {
        let constraintRect = CGSize(width: UIScreen.main.bounds.width, height: .greatestFiniteMagnitude)
        let boundingBox = self.trimmingCharacters(in: .whitespacesAndNewlines).boundingRect(with: constraintRect, options: [.usesLineFragmentOrigin, .usesFontLeading], attributes: [NSAttributedStringKey.font: UIFont.systemFont(ofSize: 14)], context: nil)
        return boundingBox.width
    }

    var stringHeight: CGFloat {
        let constraintRect = CGSize(width: UIScreen.main.bounds.width, height: .greatestFiniteMagnitude)
        let boundingBox = self.trimmingCharacters(in: .whitespacesAndNewlines).boundingRect(with: constraintRect, options: [.usesLineFragmentOrigin, .usesFontLeading], attributes: [NSAttributedStringKey.font: UIFont.systemFont(ofSize: 14)], context: nil)
        return boundingBox.height
    }
}

这就是我迄今为止所取得的成就。使用约束可能会更容易，对吗

你可以试试这个

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


    let luna = UIView()

    let titleLabel = UILabel()
    titleLabel.text = "messageTitle"
    titleLabel.font = UIFont(name: "avenirnext-demibold", size: 13)
    titleLabel.textColor = UIColor.blue
    titleLabel.numberOfLines = 0 // whole idea of self-sizing

    let titleDesc = UILabel()
    titleDesc.text = "messageDescriptionmessageDescriptionmessageDescriptionmessageDescriptionmessageDescriptionmessageDescriptionmessageDescriptionvmessageDescriptionmessageDescriptionmessageDescription"
    titleDesc.font = UIFont(name: "avenirnext-regular", size: 9)
    titleDesc.textColor = UIColor.red
    titleDesc.numberOfLines = 0

    let btn = UIButton()
    btn.setTitle("Okay", for: .normal)
    btn.setTitleColor(UIColor.blue, for: .normal)

    luna.translatesAutoresizingMaskIntoConstraints = false
    titleLabel.translatesAutoresizingMaskIntoConstraints = false
    titleDesc.translatesAutoresizingMaskIntoConstraints = false
    btn.translatesAutoresizingMaskIntoConstraints = false

    self.view.addSubview(luna)

    luna.layer.cornerRadius = 10
    luna.addSubview(titleLabel)
    luna.addSubview(titleDesc)
    luna.addSubview(btn)
    luna.layer.borderColor = UIColor.green.cgColor
    luna.layer.borderWidth = 2
    btn.setContentCompressionResistancePriority(UILayoutPriority(rawValue: 1000), for: .horizontal)

    NSLayoutConstraint.activate([

          luna.topAnchor.constraint(equalTo: view.topAnchor, constant: 30),
          luna.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20),
          luna.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20),

          titleLabel.topAnchor.constraint(equalTo: luna.topAnchor, constant: 20),
          titleLabel.leadingAnchor.constraint(equalTo: luna.leadingAnchor, constant: 20),
          titleLabel.trailingAnchor.constraint(equalTo: btn.leadingAnchor, constant: -10),


          titleDesc.topAnchor.constraint(equalTo: titleLabel.bottomAnchor, constant: 10),
          titleDesc.leadingAnchor.constraint(equalTo: luna.leadingAnchor, constant: 20),
          titleDesc.trailingAnchor.constraint(equalTo: btn.leadingAnchor, constant: -10),
          titleDesc.bottomAnchor.constraint(equalTo: luna.bottomAnchor, constant: -20),


          btn.centerYAnchor.constraint(equalTo: luna.centerYAnchor, constant: 0 ),
          btn.trailingAnchor.constraint(equalTo: luna.trailingAnchor, constant: -20),


        ])

  }

---

正如人们所说，我建议您考虑未来的汽车布局，但目前这应该满足您的要求：

    let luna = UIView()

    let titleLabel = UILabel()
    titleLabel.text = messageTitle
    titleLabel.font = UIFont(name: "avenirnext-demibold", size: 13)
    titleLabel.textColor = UIColor(hexString: "4A4A4A")
    titleLabel.numberOfLines = 0 // whole idea of self-sizing

    let titleDesc = UILabel()
    titleDesc.text = messageDescription
    titleDesc.font = UIFont(name: "avenirnext-regular", size: 9)
    titleDesc.textColor = UIColor(hexString: "4A4A4A")
    titleDesc.numberOfLines = 0

    // My mainView

    // The margins of the labels inside the luna view.
    let margins = UIEdgeInsetsMake(8, 4, 8, 4)

    // The vertical space between the two labels.
    let labelSpace: CGFloat = 4

    let titleDescSize = titleDesc.sizeThatFits(CGSize(width: screenWidth - 30 - margins.left - margins.right, height: .greatestFiniteMagnitude))

    let titleLabelSize = titleLabel.sizeThatFits(CGSize(width: screenWidth - 30 - margins.left - margins.right, height: .greatestFiniteMagnitude))

    luna.frame = CGRect(x: 16, y: 40, width: screenWidth - 30, height: titleLabelSize.height + titleDescSize.height + margins.top + margins.bottom + labelSpace)
    luna.center.x = luna.center.x
    luna.backgroundColor = .white
    luna.layer.borderWidth = luna.addShadow(radius: 11, opacity: 0.2) // Some Shadow
    luna.layer.cornerRadius = 10

    titleLabel.frame = CGRect(x: margins.left, y: margins.top, width: titleLabelSize.width, height: titleLabelSize.height)

    titleDesc.frame = CGRect(x: margins.left, y: titleLabel.frame.origin.y + titleLabel.frame.size.height + labelSpace, width: titleDescSize.width, height: titleDescSize.height)

    luna.addSubview(titleLabel)
    luna.addSubview(titleDesc)
    self.view.addSubview(luna)

---

注意：您甚至不需要使用字符串扩展名，因为UILabels能够根据其当前设置计算所需的大小。

以下是使用自动布局和堆栈视图的解决方案

let luna = UIView()

let titleLabel = UILabel()
titleLabel.text = "Title"
titleLabel.font = UIFont(name: "avenirnext-demibold", size: 13)
//titleLabel.textColor = UIColor(hexString: "4A4A4A")
titleLabel.numberOfLines = 0 // whole idea of self-sizing

let titleDesc = UILabel()
titleDesc.text = "Description"
titleDesc.font = UIFont(name: "avenirnext-regular", size: 9)
//titleDesc.textColor = UIColor(hexString: "4A4A4A")
titleDesc.numberOfLines = 0

// My mainView

luna.backgroundColor = .white
//luna.addShadow(radius: 11, opacity: 0.2) // Some Shadow
luna.layer.cornerRadius = 10

let verticalStackView = UIStackView(arrangedSubviews: [titleLabel, titleDesc])
verticalStackView.axis = .vertical

let okButton = UIButton()
okButton.setTitleColor(.blue, for: .normal)
okButton.setTitle("Okay", for: .normal)
okButton.setContentHuggingPriority(.defaultHigh, for: .horizontal) // to stretch the okay button horizontally

let horizontalStackView = UIStackView(arrangedSubviews: [verticalStackView, okButton])
horizontalStackView.axis = .horizontal

luna.addSubview(horizontalStackView)
view.addSubview(luna)

horizontalStackView.translatesAutoresizingMaskIntoConstraints = false // when using autolayout from code, this property must be false, otherwise constraint won't work
luna.translatesAutoresizingMaskIntoConstraints = false

// This method activates all constraint (when you create a constraint with anchors, by default they are disabled)
NSLayoutConstraint.activate([
        horizontalStackView.topAnchor.constraint(equalTo: luna.topAnchor, constant: 8),
        horizontalStackView.bottomAnchor.constraint(equalTo: luna.bottomAnchor, constant: -8),
        horizontalStackView.leadingAnchor.constraint(equalTo: luna.leadingAnchor, constant: 8),
        horizontalStackView.trailingAnchor.constraint(equalTo: luna.trailingAnchor, constant: -8),

        luna.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 30),
        luna.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 30),
        luna.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: -30)
    ])

---

可以通过更改堆栈视图的“间距”属性来更改视图之间的距离。i、 e.horizontalStackView.spacing=16在两个标签和OK按钮之间放置16个点的间距

您使用的是avenirnext半黑体和avenirnext常规自定义字体。但在计算字符串宽度和高度时，使用的是系统字体UIFont.systemFontofSize:14。您没有获得正确的字符串宽度和高度。titleLabel和titleDesc两个标签的宽度应小于用于填充的luna宽度

您不使用自动布局的具体原因是什么？因为像这样的布局很容易实现…@Alladinian，我知道，问题是。我不知道自动布局。你能帮忙吗？我同意@Alladinian，你为什么不使用自动布局？用它做这个视图很容易。@RicoCrescenzio。我已经提供了问题的全部内容。如果容易的话。我真的很感激你的时间，你会节省我几天的编码时间。请继续写一个解决方案我问你为什么不使用自动布局来理解你是否因为某种原因不能使用它。因为我的答案会用到它