ios - 用于动态高度中断的 UITableViewCell 约束

Question

我有一个简单的 UITableViewCell 子类，其中有一个 titleLabel 属性(该单元格有更多 View ，但为了显示问题，我只会做一个标签，因为它也会中断) .

这是我的标签代码:

    self.titleLabel = UILabel(frame: .zero)
    self.titleLabel.numberOfLines = 0
    self.titleLabel.font = UIFont.preferredFont(forTextStyle: .headline)
    self.titleLabel.textColor = UIColor.white
    self.titleLabel.adjustsFontSizeToFitWidth = false
    self.titleLabel.textAlignment = .left
    self.titleLabel.translatesAutoresizingMaskIntoConstraints = false
    self.contentView.addSubview(self.titleLabel)

    self.titleLabel.topAnchor.constraint(equalTo: self.artworkImageView.topAnchor).isActive = true
    self.titleLabel.leftAnchor.constraint(equalTo: self.artworkImageView.rightAnchor, constant: 10.0).isActive = true
    self.titleLabel.rightAnchor.constraint(equalTo: self.contentView.rightAnchor, constant: -10.0).isActive = true
    self.titleLabel.bottomAnchor.constraint(equalTo: self.contentView.bottomAnchor).isActive = true

我还像这样设置了我的 UITableView:

self.tableView.rowHeight = UITableView.automaticDimension
self.tableView.estimatedRowHeight = 50.0

但是它不断地打破约束并出现这样的错误:

"<NSLayoutConstraint:0x28211ce10 'UIView-Encapsulated-Layout-Height' UITableViewCellContentView:0x10859a4f0.height == 4.33333   (active)>"

还有更多的限制，但是这个说我的单元格内容 View 只有 4.3 的高度，但是我希望它随着标签的增长而增长。

我还尝试设置 contentHuggingPriorities 和底部 anchor 的优先级。我还把它和我在网上看到的代码或 IB 约束进行了比较，它们都设置了 4 个约束:top、left、bottom、right。 我还尝试了前导和尾随而不是左右 - 结果相同。

感谢任何帮助

这是我的完整 AlbumTableViewCell:

class AlbumTableViewCell: UITableViewCell {

    public private(set) var artworkImageView: UIImageView
    public private(set) var titleLabel: UILabel
    public private(set) var albumInfoLabel: UILabel
    public private(set) var artistNameLabel: UILabel

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

        self.artworkImageView = UIImageView(frame: .zero)
        self.titleLabel = UILabel(frame: .zero)
        self.albumInfoLabel = UILabel(frame: .zero)
        self.artistNameLabel = UILabel(frame: .zero)

        super.init(style: style, reuseIdentifier: reuseIdentifier)

        self.tintColor = UIColor.white
        self.backgroundColor = UIColor.clear

        self.contentView.backgroundColor = UIColor.barTintColor
        self.contentView.layer.masksToBounds = false
        self.contentView.layer.cornerRadius = 10.0

        self.artworkImageView.layer.cornerRadius = 10.0
        self.artworkImageView.layer.masksToBounds = true
        self.artworkImageView.contentMode = .scaleAspectFit
        self.artworkImageView.translatesAutoresizingMaskIntoConstraints = false
        self.contentView.addSubview(self.artworkImageView)

        // image view
        self.artworkImageView.leadingAnchor.constraint(equalTo: self.contentView.leadingAnchor, constant: 5).isActive = true
        self.artworkImageView.topAnchor.constraint(equalTo: self.contentView.topAnchor, constant: 5).isActive = true
        self.artworkImageView.widthAnchor.constraint(equalToConstant: 80).isActive = true
        self.artworkImageView.heightAnchor.constraint(equalToConstant: 80).isActive = true

        self.titleLabel = UILabel(frame: .zero)
        self.titleLabel.numberOfLines = 2
        self.titleLabel.font = UIFont.preferredFont(forTextStyle: .headline)
        self.titleLabel.textColor = UIColor.white
        self.titleLabel.adjustsFontSizeToFitWidth = false
        self.titleLabel.textAlignment = .left
        self.titleLabel.translatesAutoresizingMaskIntoConstraints = false
        self.contentView.addSubview(self.titleLabel)

        // title
        self.titleLabel.leadingAnchor.constraint(equalTo: self.artworkImageView.trailingAnchor, constant: 5.0).isActive = true
        self.titleLabel.topAnchor.constraint(equalTo: self.contentView.topAnchor, constant: 5.0).isActive = true
        self.titleLabel.trailingAnchor.constraint(equalTo: self.contentView.trailingAnchor, constant: -5.0).isActive = true
        self.titleLabel.heightAnchor.constraint(equalToConstant: 35).isActive = true

        self.albumInfoLabel.numberOfLines = 1
        self.albumInfoLabel.font = UIFont.preferredFont(forTextStyle: .subheadline)
        self.albumInfoLabel.textColor = UIColor.lightGray
        self.albumInfoLabel.adjustsFontSizeToFitWidth = true
        self.albumInfoLabel.textAlignment = .left
        self.albumInfoLabel.translatesAutoresizingMaskIntoConstraints = false
        self.contentView.addSubview(self.albumInfoLabel)

        // albumInfoLabel
        self.albumInfoLabel.topAnchor.constraint(equalTo: self.titleLabel.bottomAnchor, constant: 5.0).isActive = true
        self.albumInfoLabel.leadingAnchor.constraint(equalTo: self.titleLabel.leadingAnchor).isActive = true
        self.albumInfoLabel.trailingAnchor.constraint(equalTo: self.titleLabel.trailingAnchor).isActive = true
        self.albumInfoLabel.heightAnchor.constraint(equalToConstant: 35).isActive = true

        self.artistNameLabel = UILabel(frame: .zero)
        self.artistNameLabel.numberOfLines = 1
        self.artistNameLabel.font = UIFont.preferredFont(forTextStyle: .subheadline)
        self.artistNameLabel.textColor = UIColor.lightGray
        self.artistNameLabel.adjustsFontSizeToFitWidth = true
        self.artistNameLabel.textAlignment = .left
        self.artistNameLabel.translatesAutoresizingMaskIntoConstraints = false
        self.contentView.addSubview(self.artistNameLabel)

        // albumInfoLabel
        self.artistNameLabel.topAnchor.constraint(equalTo: self.albumInfoLabel.bottomAnchor, constant: 5.0).isActive = true
        self.artistNameLabel.leadingAnchor.constraint(equalTo: self.albumInfoLabel.leadingAnchor).isActive = true
        self.artistNameLabel.trailingAnchor.constraint(equalTo: self.albumInfoLabel.trailingAnchor).isActive = true
        self.artistNameLabel.heightAnchor.constraint(equalToConstant: 35).isActive = true

        let selectedView: UIView = UIView(frame: .zero)
        selectedView.backgroundColor = UIColor.gray
        selectedView.layer.cornerRadius = 10.0
        selectedView.layer.masksToBounds = false
        self.selectedBackgroundView = selectedView
    }

    override func layoutSubviews() {
        super.layoutSubviews()

        let contentViewFrame = self.contentView.frame
        let insetContentViewFrame = contentViewFrame.inset(by: UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10))
        self.contentView.frame = insetContentViewFrame

        self.selectedBackgroundView?.frame = insetContentViewFrame
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

此代码不再崩溃，但单元格不会自动调整大小(见图)。 .浅灰色区域为内容 View

此代码不再打破任何约束，但单元格也不会自动计算高度。这是我的 TableView Controller :

self.tableView.register(AlbumTableViewCell.self, forCellReuseIdentifier: "AlbumCell")
self.tableView.separatorStyle = .none
self.tableView.tableFooterView = UIView(frame: .zero)
self.tableView.rowHeight = UITableView.automaticDimension
self.tableView.estimatedRowHeight = 50.0

Answer 1

        var titleLabel = UILabel()

        contentView.addSubview(titleLabel)
        titleLabel.textColor = UIColor(red:0.32, green:0.17, blue:0.12, alpha:1.0)
        titleLabel.font = UIFont.boldSystemFont(ofSize: 16.0)
        titleLabel.translatesAutoresizingMaskIntoConstraints = false
        titleLabel.topAnchor.constraint(equalTo: marginGuide.topAnchor).isActive = true
        titleLabel.trailingAnchor.constraint(equalTo: marginGuide.trailingAnchor, constant: 8).isActive = true
        titleLabel.bottomAnchor.constraint(equalTo: marginGuide.bottomAnchor).isActive = true
        titleLabel.leadingAnchor.constraint(equalTo: marginGuide.leadingAnchor, constant: 8).isActive = true

试试这个。