UITableView_tableHeaderView_AutoLayout.swift

import UIKit

class HeaderView: UIView {
    override init(frame: CGRect) {
        super.init(frame: frame)
        setUp()
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setUp()
    }
    
    private lazy var setUp: () -> Void = {
        label.translatesAutoresizingMaskIntoConstraints = false
        addSubview(label)
        NSLayoutConstraint.activate([
            label.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 16),
            label.topAnchor.constraint(equalTo: topAnchor, constant: 16),
            trailingAnchor.constraint(equalTo: label.trailingAnchor, constant: 16),
            bottomAnchor.constraint(equalTo: label.bottomAnchor, constant: 16)
        ])
        return {}
    }()
    
    lazy var label: UILabel = {
        let label = UILabel()
        label.numberOfLines = 0
        label.lineBreakMode = .byWordWrapping
        label.text = "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
        return label
    }()
}

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(tableView)
        NSLayoutConstraint.activate([
            tableView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            view.trailingAnchor.constraint(equalTo: tableView.trailingAnchor),
            tableView.topAnchor.constraint(equalTo: view.topAnchor),
            view.bottomAnchor.constraint(equalTo: tableView.bottomAnchor)
        ])
        layoutHeaderView()
    }
    
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        headerView.layoutIfNeeded()
    }
    
    lazy var headerView = HeaderView()

    lazy var tableView: UITableView = {
        let tableView = UITableView(frame: view.bounds, style: .plain)
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "Cell")
        tableView.dataSource = self
        tableView.delegate = self
        return tableView
    }()
    
    private func layoutHeaderView() {
        headerView.translatesAutoresizingMaskIntoConstraints = false
        tableView.tableHeaderView = headerView
        NSLayoutConstraint.activate([
            headerView.topAnchor.constraint(equalTo: tableView.topAnchor),
            headerView.widthAnchor.constraint(equalTo: tableView.widthAnchor),
            headerView.centerXAnchor.constraint(equalTo: tableView.centerXAnchor)])
        headerView.layoutIfNeeded()
        tableView.tableHeaderView = headerView
    }
    
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 10
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
        cell.textLabel?.text = "Number \(indexPath.row)"
        return cell
    }
}