UIStackView 调整高度到子视图

Question

我希望 UIStackView 调整大小以适应它们的子视图（本例中为 UIImageView 和 UILabel）

    let headerView = UIStackView()
    headerView.axis = .vertical
    headerView.alignment  = .center
    headerView.distribution = .equalSpacing
    headerView.spacing = 10

    let headerImage = UIImageView(...)
    headerImage.contentMode = .scaleAspectFill
    headerImage.clipsToBounds = true
    headerImage.frame = CGRect(x: 0, y: 0, width: tableView.frame.width, height: tableView.frame.width / 1.618)

    let desciptionView = UILabel()
    desciptionView.text = "Some very long text wrapping multiple lines..."
    desciptionView.numberOfLines = 0
    desciptionView.font = UIFont.preferredFont(forTextStyle: UIFontTextStyle.body)

    headerView.addArrangedSubview(headerImage)
    headerView.addArrangedSubview(desciptionView)

    print(headerView.bounds) // always 0,0,0,0
    print(headerView.frame) // always 0,0,0,0

    tableView.tableHeaderView = headerView

(在此代码中高宽均为0)

如何实现想要的行为？

Answer 1

我发现这样做的唯一方法是将子视图的内容拥抱和抗压缩优先级设置为必需，如下所示：

    let arrangedViews = [filterLabel, image]
        .map { (view: UIView) -> UIView in
            view.setContentHuggingPriority(.required, for: .horizontal)
            view.setContentCompressionResistancePriority(.required, for: .horizontal)
            return view }

    let stack = UIStackView(arrangedSubviews: arrangedViews)
    stack.axis = .horizontal
    stack.distribution = .fill
    stack.spacing = 8

在排列好的子视图上设置这些，你确实（或者至少我做到了）得到了想要的结果。