ios - UITableViewCell 的内容 View 高度未针对动态字体进行调整(NSLayoutConstraints)

Question

我在调整表格 View 单元格以自动调整动态字体大小时遇到​​困难。请注意，我在代码中使用布局约束，而不是在 Storyboard中。

这是我的 TableView 设置代码:

tableView = UITableView(frame: .zero, style: .grouped)
tableView.register(ChatAnalyticsCell.self, forCellReuseIdentifier: ChatAnalyticsCell.reuseIdentifier)
tableView.rowHeight = UITableView.automaticDimension
tableView.estimatedRowHeight = UITableView.automaticDimension

这是我在 ChatAnalyticsCell 类中的 2 个标签和 ImageView 设置

private var iconImageView: UIImageView = {
    let imageView = UIImageView(frame: CGRect(origin: .zero,
                                              size: CGSize(width: 20, height: 20)))
    imageView.contentMode = .scaleAspectFill
    imageView.clipsToBounds = true
    imageView.translatesAutoresizingMaskIntoConstraints = false
    imageView.tintColor = UIColor(red: 0.25, green: 0.3, blue: 0.72, alpha: 1)
    return imageView
}()

private var segmentLabel: UILabel = {
    let label = UILabel()
    label.translatesAutoresizingMaskIntoConstraints = false
    label.numberOfLines = 0
    label.textColor = UIColor.gray
    label.font = UIFont.preferredFont(forTextStyle: .footnote)
    label.adjustsFontForContentSizeCategory = true

    return label
}()

private var segmentDataLabel: UILabel = {
    let label = UILabel()
    label.translatesAutoresizingMaskIntoConstraints = false
    label.numberOfLines = 0
    label.textColor = UIColor(red: 0.13, green: 0.15, blue: 0.19, alpha: 0.9)
    label.font = UIFont.preferredFont(forTextStyle: .body)
    label.adjustsFontForContentSizeCategory = true
    return label
}()

这是我添加 subview 和设置约束的函数，以便为动态字体适本地调整大小。

override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
    super.init(style: style, reuseIdentifier: reuseIdentifier)

    setupSubviews()
}


private func setupSubviews() {
    addSubview(iconImageView)
    iconImageView.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 15.0).isActive = true
    iconImageView.centerYAnchor.constraint(equalTo: contentView.centerYAnchor).isActive = true
    iconImageView.widthAnchor.constraint(equalToConstant: 20.0).isActive = true
    iconImageView.heightAnchor.constraint(equalToConstant: 20.0).isActive = true

    // Analytics segment label
    addSubview(segmentLabel)
    segmentLabel.leadingAnchor.constraint(equalTo: iconImageView.trailingAnchor, constant: 20).isActive = true
    segmentLabel.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 20).isActive = true
    segmentLabel.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -20).isActive = true

    // Segment data label
    addSubview(segmentDataLabel)
    segmentDataLabel.leadingAnchor.constraint(equalTo: segmentLabel.leadingAnchor).isActive = true
    segmentDataLabel.trailingAnchor.constraint(equalTo: segmentLabel.trailingAnchor).isActive = true
    segmentDataLabel.topAnchor.constraint(equalTo: segmentLabel.bottomAnchor, constant: 5).isActive = true
    segmentDataLabel.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: 20).isActive = true

    contentView.heightAnchor.constraint(greaterThanOrEqualToConstant: 80).isActive = true
}

请注意，当我运行代码时，没有约束被打破，但布局没有正确更新。请看截图:

Answer 1

将所有 View 添加到 contentView!

contentView.addSubview(yourView)

还有一件事 - 你可能想改变 (why?)这个约束，

segmentDataLabel.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: 20).isActive = true

到，

segmentDataLabel.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -20).isActive = true

其余约束看起来可以计算 contentView 的高度。