UITableView滚动时如何保持UITableViewCell状态？

我有一个关于扩展 UITableViewCell 的问题。
当我单击标题为“显示更多”的 UIButton 时，它正在成功扩展。
然后当我滚动 UITableView 时，我看到的情况是另一个单元格我没有点击它的 UIButton 也展开。
我有什么好主意可以解决这个问题吗？
谢谢。

class ViewController: UIViewController {

let tableView = UITableView()
let cellWithButton = "cellWithButton"
var isExpand: Bool = false
var expandIndexs: [IndexPath] = []
let text = "If you read and listen to two articles every day, your reading and listening skills can immm If you read and listen to two articles every day, your reading and listening skills can immm If you read and listen to two articles every day, your reading and listening skills can immm If you read and listen to two articles every day, your reading and listening skills can immm If you read and listen to two articles every day, your reading and listening skills can immm"

override func viewDidLoad() {
    super.viewDidLoad()

    tableView.delegate = self
    tableView.dataSource = self
    tableView.allowsSelection = false
    tableView.separatorInset = .zero
    tableView.estimatedRowHeight = 44
    tableView.rowHeight = UITableViewAutomaticDimension
    tableView.register(WithButtonTableViewCell.self, forCellReuseIdentifier: cellWithButton)


    self.view.addSubview(tableView)

    tableView.snp.makeConstraints { (make) in
        make.top.left.right.bottom.equalToSuperview()
    }
}

@objc func btnPressed(sender: UIButton) {

    let indexPath = IndexPath(row: sender.tag, section: 0)

    if self.isExpand == false {

        self.isExpand = true

        self.expandIndexs.append(indexPath)

    } else {
        self.isExpand = false

        let index = self.expandIndexs.index(of: indexPath)

        if let index = index {
            self.expandIndexs.remove(at: index)
        }
    }

    tableView.beginUpdates()
    tableView.reloadRows(at: [indexPath], with: .none)
    tableView.endUpdates()

}
}

extension ViewController: UITableViewDelegate, UITableViewDataSource {

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 10
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: cellWithButton, for: indexPath) as! WithButtonTableViewCell

    if self.expandIndexs.contains(indexPath) {
        cell.cellIsExpand = self.isExpand
    }
    cell.titleLabel.text = text
    cell.expandButton.addTarget(self, action: #selector(btnPressed), for: .touchUpInside)
    cell.expandButton.tag = indexPath.row
    cell.layoutIfNeeded()

    return cell
}
}


class WithButtonTableViewCell: UITableViewCell {

var cellIsExpand: Bool = false

let titleLabel: UILabel = { () -> UILabel in
    let ui = UILabel()
    ui.textColor = UIColor.black
    return ui
}()

let expandButton: UIButton = { () -> UIButton in
    let ui = UIButton()
    ui.setTitleColor(UIColor.blue, for: .normal)
    return ui
}()

override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code
}

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

    // Configure the view for the selected state
}

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

    loadUI()
    loadLayout()
}

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

}

override func layoutIfNeeded() {
    super.layoutIfNeeded()

    if cellIsExpand == true {
        titleLabel.numberOfLines = 0
        expandButton.setTitle("Close.", for: .normal)
    }else{
        titleLabel.numberOfLines = 2
        expandButton.setTitle("Show More.", for: .normal)
    }
}

func loadUI() {

    self.addSubview(titleLabel)
    self.addSubview(expandButton)
}

func loadLayout() {

    titleLabel.snp.makeConstraints { (make) in
        make.top.left.equalTo(15)
        make.right.equalTo(-15)
    }

    expandButton.snp.makeConstraints { (make) in
        make.top.equalTo(titleLabel.snp.bottom).offset(10)
        make.left.equalTo(10)
        make.right.equalTo(-15)
        make.bottom.equalTo(-15)            
    }
}
}