将项目包裹在多行的水平 UIStackView 中

Question

我正在开发一个显示UITableView项目的 iOS 应用程序。每行将显示具有不同宽度的标签列表（由​​标签的文本长度给出）。我可以将所有标签水平放置，UIStackView但我希望它们包装在多行而不是单个可滚动的行上。基本上我对类似于 FlexBoxflex-wrap属性的功能感兴趣。

我附上了一张图片供参考。

任何想法如何实现这一目标？

Answer 1

有许多不同的方法来解决这个问题。

一种方法 -不使用堆栈视图：

• 将您的标签添加到“容器”视图
• 从x = 0和开始y = 0
• 遍历标签，计算新x值（标签宽度 + 标签之间所需的间距）
• 如果新的x将超过容器的边缘，请重置x = 0并添加所需的高度y以“移动到下一行”
• 标签布置好后，设置容器视图的高度

这是一个简单的例子：

class TagLabelsViewController: UIViewController {

    let containerView: UIView = {
        let v = UIView()
        return v
    }()

    let tagNames: [String] = [
        "First Tag",
        "Second",
        "Third Tag",
        "Fourth",
        "The Fifth Tag",
        "Sixth",
        "Seventh",
        "Tag Eight",
        "Here are some Letter Tags",
        "A", "B", "C", "D", "E", "F", "G", "H", "I", "J",
        "Nine",
        "Ten",
        "Eleven",
        "Tag Twelve",
        "Tag 13",
        "Fourteen",
        "Fifteen",
        "Sixteen",
        "Seventeen",
        "Eightteen",
        "Nineteen",
        "Last Tag",
    ]

    var tagLabels = [UILabel]()

    let tagHeight:CGFloat = 30
    let tagPadding: CGFloat = 16
    let tagSpacingX: CGFloat = 8
    let tagSpacingY: CGFloat = 8

    // container view height will be modified when laying out subviews
    var containerHeightConstraint: NSLayoutConstraint = NSLayoutConstraint()

    override func viewDidLoad() {
        super.viewDidLoad()

        // add the container view
        view.addSubview(containerView)

        // give it a background color so we can see it
        containerView.backgroundColor = .yellow

        // use autolayout
        containerView.translatesAutoresizingMaskIntoConstraints = false

        // initialize height constraint - actual height will be set later
        containerHeightConstraint = containerView.heightAnchor.constraint(equalToConstant: 10.0)

        // constrain container safe-area top / leading / trailing to view with 20-pts padding
        let g = view.safeAreaLayoutGuide

        NSLayoutConstraint.activate([
            containerView.topAnchor.constraint(equalTo: g.topAnchor, constant: 20.0),
            containerView.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
            containerView.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),
            containerHeightConstraint,
        ])

        // add the buttons to the scroll view
        addTagLabels()

    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()

        // call this here, after views have been laid-out
        // this will also be called when the size changes, such as device rotation,
        // so the buttons will "re-layout"
        displayTagLabels()

    }

    func addTagLabels() -> Void {

        for j in 0..<self.tagNames.count {

            // create a new label
            let newLabel = UILabel()

            // set its properties (title, colors, corners, etc)
            newLabel.text = tagNames[j]
            newLabel.textAlignment = .center
            newLabel.backgroundColor = UIColor.cyan
            newLabel.layer.masksToBounds = true
            newLabel.layer.cornerRadius = 8
            newLabel.layer.borderColor = UIColor.red.cgColor
            newLabel.layer.borderWidth = 1

            // set its frame width and height
            newLabel.frame.size.width = newLabel.intrinsicContentSize.width + tagPadding
            newLabel.frame.size.height = tagHeight

            // add it to the scroll view
            containerView.addSubview(newLabel)

            // append it to tagLabels array
            tagLabels.append(newLabel)

        }

    }

    func displayTagLabels() {

        let containerWidth = containerView.frame.size.width

        var currentOriginX: CGFloat = 0
        var currentOriginY: CGFloat = 0

        // for each label in the array
        tagLabels.forEach { label in

            // if current X + label width will be greater than container view width
            //  "move to next row"
            if currentOriginX + label.frame.width > containerWidth {
                currentOriginX = 0
                currentOriginY += tagHeight + tagSpacingY
            }

            // set the btn frame origin
            label.frame.origin.x = currentOriginX
            label.frame.origin.y = currentOriginY

            // increment current X by btn width + spacing
            currentOriginX += label.frame.width + tagSpacingX

        }

        // update container view height
        containerHeightConstraint.constant = currentOriginY + tagHeight

    }

}

结果：

它非常简单，通过代码中的注释，您应该能够根据自己的需要进行调整。

如果您想要一个“预先构建”的解决方案，也许具有更多功能，请搜索

swift left aligned tags view

想出了很多比赛。这个（我与它无关）看起来很有趣：https : //github.com/ElaWorkshop/TagListView