UITableView header align with cell bounds

Question

I am generating a custom header view for my UITableView which has two horizontal lines up & down and a UILabel in between.

    let lineWidth = tableView.bounds.width //This is not correct, will never align with UITableViewCell
    let offset = (tableView.bounds.width - lineWidth)/2 //This will always yield 0, but my question is to compute line width that aligns with UITableViewCell as shown in the image attached to this question.
    let topLine = UIView(frame: CGRect(x: offset, y: 0, width: lineWidth, height: 1))
    topLine.backgroundColor = UIColor.white
    let bottomLine = UIView(frame: CGRect(x: offset, y: 49.0, width: lineWidth, height: 1))
    bottomLine.backgroundColor = UIColor.white
    let label = UILabel(frame: CGRect(x: 0, y: 1.0, width: tableView.bounds.width, height: 48.0))
    label.textColor = UIColor.white

    let headerView = UIView(frame: CGRect(x: 0, y: 0, width: tableView.bounds.width, height: 50))
    headerView.addSubview(topLine)
    headerView.addSubview(label)
    headerView.addSubview(bottomLine)

Problem: I need the top & bottom lines to align with UITableViewCell bounds in the section as shown in the picture below. What I get with the code above is horizontal lines that cover the entire width of UITableView. How do I achieve it?

EDIT: Some answers here describe an arbitrary offset value, but the heart of the problem is how to compute offset that aligns with UITableViewCell bounds in the section? In other words, I need exact width of UITableViewCell's that go into the section.

Answer 1

Your Offset will be practically zero as you are subtracting the same things

let lineWidth = tableView.bounds.width
let offset = (tableView.bounds.width - lineWidth)/2
let topLine = UIView(frame: CGRect(x: offset, y: 0, width: lineWidth, height: 1)) // this line gonna give offset as zero and width of full tableview width

Change this to the below code and try

let lineWidth = tableView.bounds.width - 20
let topLine = UIView(frame: CGRect(x: 10, y: 0, width: lineWidth, height: 1))

Answer 2

It seems the issue with the position of your top & bottom lines. As per the calculation of offset it always set to 0 for top & bottom lines. So it would be better to remove that offset calculation and you can add some desired static value as a x for CGRect of top & bottom lines.

As far as we are going to move the position of x for the top & bottom line don't forget to remove the added value for x position from the width of the top & bottom lines.

let yourLine = UIView(frame: CGRect(x: some_value, y: 0, width: Int(lineWidth - (some_value * 2)), height: 1))

The best practice is you can use some variables to achieve this.