以编程方式动态计算自定义 TableView Cell 的高度？

Question

我有以下代码来定义我的自定义 tableView 单元格 Class:

import UIKit

import ChameleonFramework

class IsectionsCustomTableViewCell: UITableViewCell {

    let sectionDesignationLabelTopPadding: CGFloat = 10

    let sectionDesignationLabelLeftPadding: CGFloat = 10

    let sectionDesignationLabelRightPadding: CGFloat = 10

    let depthOfSectionLabelTopPadding: CGFloat = 5

    let depthOfSectionLabelLeftPadding: CGFloat = 10

    let depthOfSectionLabelRightPadding: CGFloat = 2.50

    let webThicknessLabelTopPadding: CGFloat = 5

    let webThicknessLabelLeftPadding: CGFloat = 2.50

    let webThicknessLabelRightPadding: CGFloat = 10

    let widthOfSectionLabelTopPadding: CGFloat = 5

    let widthOfSectionLabelLeftPadding: CGFloat = 10

    let widthOfSectionLabelRightPadding: CGFloat = 2.50

    let sectionFlangeThicknessLabelTopPadding: CGFloat = 5

    let sectionFlangeThicknessLabelLeftPadding: CGFloat = 2.5

    let sectionFlangeThicknessLabelRightPadding: CGFloat = 10

    let sectionMassPerMetreLabelTopPadding: CGFloat = 5

    let sectionMassPerMetreLabelLeftPadding: CGFloat = 10

    let sectionMassPerMetreLabelRightPadding: CGFloat = 2.5

    var tableCellContainer: UIView = {

        let container = UIView()

        container.translatesAutoresizingMaskIntoConstraints = false

        container.backgroundColor = UIColor.flatPink()

        return container

    }()

    var sectionDesignationLabel: UILabel = {

        let label = UILabel()

        label.numberOfLines = 0

        label.lineBreakMode = NSLineBreakMode.byWordWrapping

        label.backgroundColor = UIColor.yellow

        label.textAlignment = .left

        label.translatesAutoresizingMaskIntoConstraints = false

        label.textColor = UIColor(hexString: "#F27E63")

        return label

    }()

    var depthOfSectionLabel: UILabel = {

        let label = UILabel()

        label.backgroundColor = UIColor.blue

        label.numberOfLines = 0

        label.textAlignment = .left

        label.lineBreakMode = NSLineBreakMode.byWordWrapping

        label.translatesAutoresizingMaskIntoConstraints = false

        label.textColor = UIColor(hexString: "#F27E63")

        return label

    }()

    var widthOfSectionLabel: UILabel = {

        let label = UILabel()

        label.numberOfLines = 0

        label.textAlignment = .left

        label.lineBreakMode = NSLineBreakMode.byWordWrapping

        label.translatesAutoresizingMaskIntoConstraints = false

        label.textColor = UIColor(hexString: "#F27E63")

        label.backgroundColor = UIColor.gray

        return label

    }()

    var sectionWebThicknessLabel: UILabel = {

        let label = UILabel()

        label.translatesAutoresizingMaskIntoConstraints = false

        label.textColor = UIColor(hexString: "#F27E63")

        label.backgroundColor = UIColor.cyan

        label.textAlignment = .left

        label.numberOfLines = 0

        label.lineBreakMode = NSLineBreakMode.byWordWrapping

        return label

    }()

    var sectionFlangeThicknessLabel: UILabel = {

        let label = UILabel()

        label.translatesAutoresizingMaskIntoConstraints = false

        label.textColor = UIColor(hexString: "#F27E63")

        label.lineBreakMode = NSLineBreakMode.byWordWrapping

        label.numberOfLines = 0

        label.textAlignment = .left

        label.backgroundColor = UIColor.green

        return label

    }()

    var sectionMassPerMetreLabel: UILabel = {

        let label = UILabel()

        label.translatesAutoresizingMaskIntoConstraints = false

        label.textColor = UIColor(hexString: "#F27E63")

        label.lineBreakMode = NSLineBreakMode.byWordWrapping

        label.numberOfLines = 0

        label.textAlignment = .left

        label.backgroundColor = UIColor.white

        return label

    }()

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

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

        addSubview(tableCellContainer)

        tableCellContainer.addSubview(sectionDesignationLabel)

        tableCellContainer.addSubview(depthOfSectionLabel)

        tableCellContainer.addSubview(sectionWebThicknessLabel)

        tableCellContainer.addSubview(widthOfSectionLabel)

        tableCellContainer.addSubview(sectionFlangeThicknessLabel)

        tableCellContainer.addSubview(sectionMassPerMetreLabel)

        applyAppropriateSizeAndConstraintsForCellItems()

    }

    required init?(coder aDecoder: NSCoder) {

        fatalError("init(coder:) has not been implemented")

    }

    func applyAppropriateSizeAndConstraintsForCellItems() {

        NSLayoutConstraint.activate([

            tableCellContainer.topAnchor.constraint(equalTo: self.topAnchor),

            tableCellContainer.leftAnchor.constraint(equalTo: self.leftAnchor),

            tableCellContainer.rightAnchor.constraint(equalTo: self.rightAnchor),

            tableCellContainer.bottomAnchor.constraint(equalTo: self.bottomAnchor),

            sectionDesignationLabel.topAnchor.constraint(equalTo: tableCellContainer.topAnchor, constant: sectionDesignationLabelTopPadding),

            sectionDesignationLabel.leftAnchor.constraint(equalTo: tableCellContainer.leftAnchor, constant: sectionDesignationLabelLeftPadding),

            sectionDesignationLabel.rightAnchor.constraint(equalTo: tableCellContainer.rightAnchor, constant: -1*sectionDesignationLabelRightPadding),

            depthOfSectionLabel.topAnchor.constraint(equalTo: sectionDesignationLabel.bottomAnchor, constant: depthOfSectionLabelTopPadding),

            depthOfSectionLabel.leftAnchor.constraint(equalTo: tableCellContainer.leftAnchor, constant: depthOfSectionLabelLeftPadding),

            depthOfSectionLabel.rightAnchor.constraint(equalTo: tableCellContainer.superview!.centerXAnchor, constant: -1*depthOfSectionLabelRightPadding),

            sectionWebThicknessLabel.topAnchor.constraint(equalTo: sectionDesignationLabel.bottomAnchor, constant: webThicknessLabelTopPadding),

            sectionWebThicknessLabel.leftAnchor.constraint(equalTo: tableCellContainer.superview!.centerXAnchor, constant: webThicknessLabelLeftPadding),

            sectionWebThicknessLabel.rightAnchor.constraint(equalTo: tableCellContainer.rightAnchor, constant: -1*webThicknessLabelRightPadding),

            widthOfSectionLabel.topAnchor.constraint(equalTo: depthOfSectionLabel.bottomAnchor, constant: widthOfSectionLabelTopPadding),

            widthOfSectionLabel.leftAnchor.constraint(equalTo: tableCellContainer.leftAnchor, constant: widthOfSectionLabelLeftPadding),

            widthOfSectionLabel.rightAnchor.constraint(equalTo: tableCellContainer.superview!.centerXAnchor, constant: -1*widthOfSectionLabelRightPadding),

            sectionFlangeThicknessLabel.topAnchor.constraint(equalTo: sectionWebThicknessLabel.bottomAnchor, constant: sectionFlangeThicknessLabelTopPadding),

            sectionFlangeThicknessLabel.leftAnchor.constraint(equalTo: tableCellContainer.superview!.centerXAnchor, constant: sectionFlangeThicknessLabelLeftPadding),

            sectionFlangeThicknessLabel.rightAnchor.constraint(equalTo: tableCellContainer.rightAnchor, constant: -1*sectionFlangeThicknessLabelRightPadding),

            sectionMassPerMetreLabel.topAnchor.constraint(equalTo: widthOfSectionLabel.bottomAnchor, constant: sectionMassPerMetreLabelTopPadding),

            sectionMassPerMetreLabel.leftAnchor.constraint(equalTo: tableCellContainer.leftAnchor, constant: sectionMassPerMetreLabelLeftPadding),

            sectionMassPerMetreLabel.rightAnchor.constraint(equalTo: tableCellContainer.superview!.centerXAnchor, constant: -1*sectionMassPerMetreLabelRightPadding)

            ])

    }

}

当我为所有大于 150 的单元格指定高度时，上述方法效果很好（请参阅附图）。

但是，我想要实现的是自定义 TableViewCell Class 中代码中定义的 tableCellContainer UIView 能够根据其中的子视图计算其高度。因此，我基于所附图像，希望能够计算出 sectionDesignationLabelTopPadding + + sectionDesignationLabelHeight + depthOfSectionLabelTopPadding + depthOfSectionLabelHeight + widthOfSectionLabelTopPadding + widthOfSectionLabelHeight + massPerMetreLabelTopPadding + massPerMetreLabelHeight 的高度。然后将总数与 sectionDesignationLabelTopPadding + sectionDesignationLabelHeight + webThicknessLabelTopPadding + webThicknessLabelHeight + flangeThicknessLabelTopPadding + flangeThicknessLabelHeight 的总数进行比较。我想将两者之间的最大总和设置为 tableCellContainer UIView 的高度。

我尝试做的事情如下：

在包含tableView的ViewController里面，具体是在cellForRowAt indexPath函数里面，计算每个label的高度，然后把总和的最大值设置为容器的高度。但是，这没有用，因为它为每个 UILabel 项目的高度返回了错误的值。

有人可以指导我如何实现我正在寻找的最佳位置和方法，非常感谢高级吗？

此致，沙迪.

Answer 1

首先分享的就是EPIC尺寸代码。您应该始终从更小的代码开始，以测试您想要学习的新事物。

其次，您正在寻找的功能称为Self sizing tableView cell。有很多教程可以帮助您实现这一目标。

但我很快就会向你解释：

首先，所有子视图都应该具有 self-sizing 的能力（如 UILabel 和 UIButton 或您自己的自定义类）或具有确切的constraints.
那么它们都应该以某种方式与单元格（或单元格本身）的 contentView 相关。像这样：V: contentViewTop-subview1-subview2-subview3-contentViewBottom
然后如果你将tableView.rowHeight设置为UITableView.automaticDimension，它会自动获取所有子视图的固有内容大小并将其应用于单元格高度。

本教程可以帮助您更好地理解更多细节：

Self-sizing-table-view-cells

以编程方式动态计算自定义 TableView Cell 的高度？

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