UISwitch in headerview of UITableView is changing state but not calling event handle method

Question

I am working on a project which has UITableView with UISwitch on headerview. Following is my code for header view. I have tried different questions regarding button click event on headerview but none of the solutions seems to work.

If it helps, I am setting UITableView header height.

func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
    return 100;
}

Here is the code for my header.

class NotificationSettingsTableHeaderView : UIView, ViewProtocol {

    //other controls
    var mainSwitch : UISwitch!
    var contentView : UIView!

    weak var temp: SettingCellDelegate?

    func handle(sender: UISwitch) {

     // ----------- THIS METHOD IS NOT GETTING CALLED ------------
        if(sender.isOn){
            print("IS ON")
        }
        else{
            print("IS OFF")
        }

    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        addSubviews()
        makeConstraints()
    }

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


    func addSubviews() {

        contentView = UIView()

    // Other control initialization
        mainSwitch = UISwitch()
        mainSwitch.addTarget(self, action: #selector(NotificationSettingsTableHeaderView.handle(sender:)), for: UIControlEvents.valueChanged)
        contentView.addSubview(mainSwitch)

    }

    func makeConstraints() {

        let screen = UIScreen.main.bounds

        contentView.frame = CGRect(x: 0, y: 0, width: screen.width, height: 80)
        mainSwitch.snp.makeConstraints { (make) in
            make.centerY.equalTo(contentView)
            make.right.equalTo(contentView).offset(-10)
        }
        // other code

    }    
}

Edited

I am adding contentview to header using following code.

func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView {

    let cell = NotificationSettingsTableHeaderView()
    let cat = preferenceSection.allSections[section]
    cell.label.text = cat.getTitle()
    cell.descLabel.text = cat.getSubtitle()
    return cell.contentView
}

Here is how my header view look. I am even able to turn on/off switch

Answer 1

Check that you have your UISwitch in your UIView hierarchy, as @DonMag says, seems that you have forgot add your contentView to view hierarchy, Your handle method is an instance method, don't a class method, so

Change this line in your addSubviews method

mainSwitch.addTarget(self, action: #selector(NotificationSettingsTableHeaderView.handle(sender:)), for: UIControlEvents.valueChanged)

by this one

mainSwitch.addTarget(self, action: #selector(self.handle(sender:)), for: UIControlEvents.valueChanged)

Updated 1

You need return your NotificationSettingsTableHeaderView object and you are returning the contentView instead

change this line in your viewForHeaderInSection method of your UITableViewDelegate

return cell.contentView

by this one

return cell

Updated 2

func addSubviews() {

        contentView = UIView()

    // Other control initialization
        mainSwitch = UISwitch()
        mainSwitch.addTarget(self, action: #selector(NotificationSettingsTableHeaderView.handle(sender:)), for: UIControlEvents.valueChanged)
        self.addSubview(mainSwitch)
    }

func makeConstraints() {

    mainSwitch.snp.makeConstraints { (make) in
        make.centerY.equalTo(self)
        make.right.equalTo(self).offset(-10)
    }
    // other code

}