ios - Swift 3で失敗するUITableViewCellの高さを動的に調整する

Question

カスタマイズされた UITableViewCell があり、ラベルのテキスト コンテンツに従って高さを更新したいと考えています。
しかし、私は ViewController ViewDidLoad でこのコードを使用しようとしています:

  tableView.register(ChatRightTextTableViewCell.self, forCellReuseIdentifier: ChatRightTextTableViewCell.identifier)
  tableView.estimatedRowHeight = 100.0
  tableView.rowHeight = UITableViewAutomaticDimension

高さを更新していないようです。
セル制約の何が問題になっていますか?
ありがとう。

import snapKit
import UIKit

class ChatRightTextTableViewCell: UITableViewCell {

static let identifier = "ChatRightTextTableViewCell"
var cellHeight: CGFloat = 0

var labelContent:UILabel = { ()->UILabel in
    let ui:UILabel = GeneratorLabel()
    ui.textColor = UIColor(red:0.20, green:0.20, blue:0.20, alpha:1.00)
    ui.backgroundColor = UIColor.white
    ui.font = defaultTextFont
    ui.numberOfLines = 0
    ui.lineBreakMode = NSLineBreakMode.byCharWrapping
    ui.layer.cornerRadius = defaultButtonRadius
    ui.layer.masksToBounds = true
    return ui
}()

var labelDatetime:UILabel = { ()->UILabel in
    let ui = GeneratorLabel()
    ui.font = defaultMessageTimeFont
    ui.textColor = defaultChatTimeColor
    ui.numberOfLines = 0
    return ui
}()

var icon:UIImageView = { ()->UIImageView in
    let ui = GeneratorAvatarImageView()
    ui.isUserInteractionEnabled = true
    return ui
}()

override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
    super.init(style: style, reuseIdentifier: reuseIdentifier)
    loadContent()
}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

override func layoutSubviews() {
    super.layoutSubviews()
    loadVFL()
}

override func awakeFromNib() {
    super.awakeFromNib()
}

override func setSelected(_ selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Configure the view for the selected state
}


func loadContent() {
    backgroundColor = defaultBackgroundColor
    selectionStyle = .none
    contentView.addSubview(labelContent)
    contentView.addSubview(labelDatetime)
    contentView.addSubview(icon)
}

func loadVFL() {

    let datetimeHeight:CGFloat = UIScreen.main.bounds.height*0.0195 //13

    let contentWidth:CGFloat = contentView.bounds.width*0.62  //254.5
    let iconLeftPadding:CGFloat = contentView.bounds.width*0.0266 //15
    let contentAndDatePadding:CGFloat = UIScreen.main.bounds.height*0.0089 //6
    let dateAndBottomPaddding:CGFloat = UIScreen.main.bounds.height*0.0090 //6
    let topPadding:CGFloat            = UIScreen.main.bounds.height*0.0149 //10
    let nameLabelBottomPadding:CGFloat = UIScreen.main.bounds.height*0.0075 //5

    let views = DictionaryOfInstanceVariables(self, objects: "labelContent","labelDatetime","icon")
    let metrics = ["padding":iconLeftPadding,"contentAndDatePadding":contentAndDatePadding,"dateAndBottomPaddding":dateAndBottomPaddding,"nameLabelBottomPadding":nameLabelBottomPadding,"topPadding":topPadding]

    labelContent.frame = CGRect(x: 0, y: 0, width: contentWidth, height: CGFloat.greatestFiniteMagnitude)
    labelContent.sizeToFit()

    icon.snp.makeConstraints { (make) -> Void in
        make.width.equalTo(defaultChatroomIconWidth)
        make.height.equalTo(defaultChatroomIconWidth)
        make.centerY.equalToSuperview()
    }

    labelDatetime.snp.makeConstraints { (make) in
        make.height.equalTo(datetimeHeight)
    }

    labelContent.backgroundColor = UIColor.red
    addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:[labelContent]-padding-[icon]-padding-|", options: [], metrics: metrics, views: views))
    addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:[labelDatetime]-padding-[icon]-padding-|", options: [], metrics: metrics, views: views))
    addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|-topPadding-[labelContent]-contentAndDatePadding-[labelDatetime]-dateAndBottomPaddding-|", options: [], metrics: metrics, views: views))
    addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|-topPadding-[icon]", options: [], metrics: metrics, views: views))
}
}