[iphone] How to set the height of table header in UITableView?

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()
    sizeHeaderToFit()
}

private func sizeHeaderToFit() {
    let headerView = tableView.tableHeaderView!

    headerView.setNeedsLayout()
    headerView.layoutIfNeeded()

    let height = headerView.systemLayoutSizeFitting(UILayoutFittingCompressedSize).height
    var frame = headerView.frame
    frame.size.height = height
    headerView.frame = frame

    tableView.tableHeaderView = headerView
}

More details can be found here