【发布时间】：2019-10-21 07:54:18
【问题描述】：
我有如下视图层次结构；
UITableViewCell ->
-> UIView -> UIStackView (axis: vertical, distribution: fill)
-> UIStackView (axis: horizontal, alignment: top, distribution: fillEqually)
-> UIView -> UIStackView(axis:vertical, distribution: fill)
-> TwoLabelView
我的问题是标签不能超过一行。我阅读了 SO 中的每一个问题，也尝试了每一种可能性，但都没有奏效。在下面的屏幕截图中，在左上角的框中，应该有两对标签，但其中一个没有显示。
我的问题是如何在第一个框中实现多行（左右两边）？
如果我将顶部堆栈视图分布更改为 fillProportionally，标签会变为多行，但第一个框的最后一个元素与框本身之间会有间隙
我的第一个顶部堆栈视图
//This is the Stackview used just below UITableViewCell
private let stackView: UIStackView = {
let s = UIStackView()
s.distribution = .fill
s.axis = .vertical
s.spacing = 10
s.translatesAutoresizingMaskIntoConstraints = false
return s
}()
//This is used to create two horizontal box next to each other
private let myStackView: UIStackView = {
let s = UIStackView()
s.distribution = .fillEqually
s.spacing = 10
s.axis = .horizontal
//s.alignment = .center
s.translatesAutoresizingMaskIntoConstraints = false
return s
}()
UILabel 类：
fileprivate class FixAutoLabel: UILabel {
override func layoutSubviews() {
super.layoutSubviews()
if(self.preferredMaxLayoutWidth != self.bounds.size.width) {
self.preferredMaxLayoutWidth = self.bounds.size.width
}
}
}
@IBDesignable class TwoLabelView: UIView {
var topMargin: CGFloat = 0.0
var verticalSpacing: CGFloat = 3.0
var bottomMargin: CGFloat = 0.0
@IBInspectable var firstLabelText: String = "" { didSet { updateView() } }
@IBInspectable var secondLabelText: String = "" { didSet { updateView() } }
fileprivate var firstLabel: FixAutoLabel!
fileprivate var secondLabel: FixAutoLabel!
override init(frame: CGRect) {
super.init(frame: frame)
setUpView()
}
required public init?(coder: NSCoder) {
super.init(coder:coder)
setUpView()
}
override func prepareForInterfaceBuilder() {
super.prepareForInterfaceBuilder()
setUpView()
}
func setUpView() {
firstLabel = FixAutoLabel()
firstLabel.font = UIFont.systemFont(ofSize: 18.0, weight: UIFont.Weight.bold)
firstLabel.numberOfLines = 0
firstLabel.lineBreakMode = NSLineBreakMode.byTruncatingTail
secondLabel = FixAutoLabel()
secondLabel.font = UIFont.systemFont(ofSize: 13.0, weight: UIFont.Weight.regular)
secondLabel.numberOfLines = 1
secondLabel.lineBreakMode = NSLineBreakMode.byTruncatingTail
addSubview(firstLabel)
addSubview(secondLabel)
// we're going to set the constraints
firstLabel .translatesAutoresizingMaskIntoConstraints = false
secondLabel.translatesAutoresizingMaskIntoConstraints = false
// pin both labels' left-edges to left-edge of self
firstLabel.leftAnchor.constraint(equalTo: leftAnchor, constant: 0.0).isActive = true
secondLabel.leftAnchor.constraint(equalTo: leftAnchor, constant: 0.0).isActive = true
// pin both labels' right-edges to right-edge of self
firstLabel.rightAnchor.constraint(equalTo: rightAnchor, constant: 0.0).isActive = true
secondLabel.rightAnchor.constraint(equalTo: rightAnchor, constant: 0.0).isActive = true
// pin firstLabel to the top of self + topMargin (padding)
firstLabel.topAnchor.constraint(equalTo: topAnchor, constant: topMargin).isActive = true
// pin top of secondLabel to bottom of firstLabel + verticalSpacing
secondLabel.topAnchor.constraint(equalTo: firstLabel.bottomAnchor, constant: verticalSpacing).isActive = true
// pin bottom of self to bottom of secondLabel + bottomMargin (padding)
bottomAnchor.constraint(equalTo: secondLabel.bottomAnchor, constant: bottomMargin).isActive = true
// call common "refresh" func
updateView()
}
func updateView() {
firstLabel.preferredMaxLayoutWidth = self.bounds.width
secondLabel.preferredMaxLayoutWidth = self.bounds.width
firstLabel.text = firstLabelText
secondLabel.text = secondLabelText
firstLabel.sizeToFit()
secondLabel.sizeToFit()
setNeedsUpdateConstraints()
}
override open var intrinsicContentSize : CGSize {
// just has to have SOME intrinsic content size defined
// this will be overridden by the constraints
return CGSize(width: 1, height: 1)
}
}
UIView -> UIStackView 类
class ViewWithStack: UIView {
let verticalStackView: UIStackView = {
let s = UIStackView()
s.distribution = .fillEqually
s.spacing = 10
s.axis = .vertical
s.translatesAutoresizingMaskIntoConstraints = false
return s
}()
override init(frame: CGRect) {
super.init(frame: frame)
self.translatesAutoresizingMaskIntoConstraints = false
self.backgroundColor = UIColor.white
self.layer.cornerRadius = 6.0
self.layer.applySketchShadow(color: UIColor(red:0.56, green:0.56, blue:0.56, alpha:1), alpha: 0.2, x: 0, y: 0, blur: 10, spread: 0)
addSubview(verticalStackView)
let lessThan = verticalStackView.bottomAnchor.constraint(lessThanOrEqualTo: self.bottomAnchor, constant: 0)
lessThan.priority = UILayoutPriority(1000)
lessThan.isActive = true
verticalStackView.leftAnchor.constraint(equalTo: self.leftAnchor,constant: 0).isActive = true
verticalStackView.rightAnchor.constraint(equalTo: self.rightAnchor,constant: 0).isActive = true
verticalStackView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
verticalStackView.layoutMargins = UIEdgeInsets(top: 10, left: 20, bottom: 10, right: 20)
verticalStackView.isLayoutMarginsRelativeArrangement = true
}
convenience init(orientation: NSLayoutConstraint.Axis,labelsArray: [UIView]) {
self.init()
verticalStackView.axis = orientation
for label in labelsArray {
verticalStackView.addArrangedSubview(label)
}
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
示例控制器类（这是整个项目的最小化版本）：
class ViewController: UIViewController, UITableViewDelegate,UITableViewDataSource {
@IBOutlet weak var tableView: UITableView!
let viewWithStack = BoxView()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
tableView.delegate = self
tableView.dataSource = self
tableView.register(TableViewCell.self, forCellReuseIdentifier: "myCell")
tableView.rowHeight = UITableView.automaticDimension
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 2
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell: TableViewCell = tableView.dequeueReusableCell(withIdentifier: "myCell") as! TableViewCell
if (indexPath.row == 0) {
cell.setup(viewWithStack: self.viewWithStack)
} else {
cell.backgroundColor = UIColor.black
}
return cell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
//return 500
if ( indexPath.row == 0) {
return UITableView.automaticDimension
} else {
return 40
}
}
}
编辑 我创建了一个最小的项目，然后我发现我的问题是我的项目实现了 heightForRow 函数，该函数覆盖了 UITableViewAutomaticDimension，因此它为我的组件提供了错误的高度。我想我应该看看如何获得组件的高度大小？因为我无法删除解决我的问题的heightForRow 函数。
示例项目链接 https://github.com/emreond/tableviewWithStackView/tree/master/tableViewWithStackViewEx
当您打开视图调试器时，示例项目具有雄心勃勃的布局。我想当我修复它们时，一切都会好起来的。
【问题讨论】：
-
正如我在您的类似问题 (stackoverflow.com/questions/58413397/…) 中提到的，仅查看代码片段时很难提供帮助。将minimal reproducible example 放在一起，以便有人可以确切地看到发生了什么。
-
我正在做一个非常大的项目，我什至无法重现该示例，但我会尝试。
-
看起来你有很多事情是不必要的。很少需要设置
.preferredMaxLayoutWidth或调用sizeToFit()或setNeedsUpdateConstraints()。尝试简化您正在做的事情。 -
我编辑了我的问题。你能检查一下吗？
-
为什么要实施
heightForRowAt？您可以在下面的示例中看到它是不需要的。
标签： ios swift uilabel uistackview