iOS - subivew不能在UITableViewCell中居中

class CustomTableViewCell: UITableViewCell {
    var customSubview: UIView!
    
    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        
        // 创建自定义的subview
        customSubview = UIView()
        customSubview.backgroundColor = UIColor.red
        
        // 添加subview到cell中
        addSubview(customSubview)
        
        // 使用Auto Layout设置subview居中
        customSubview.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            customSubview.centerXAnchor.constraint(equalTo: centerXAnchor),
            customSubview.centerYAnchor.constraint(equalTo: centerYAnchor),
            customSubview.widthAnchor.constraint(equalToConstant: 100),
            customSubview.heightAnchor.constraint(equalToConstant: 100)
        ])
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

// 在UITableView的数据源方法中使用CustomTableViewCell
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath) as! CustomTableViewCell
    
    // 设置cell的数据
    
    return cell
}