Swift 之返回按钮

1、左侧图标+文字

 private lazy var backButton: UIButton = {
    
    let button = UIButton()
    button.setImage(ImageLoader.image(named: "back"), for: .normal)
    button.imageView?.contentMode = .scaleAspectFit
    button.imageEdgeInsets = UIEdgeInsets(top: 0, left: 8, bottom: 0, right: 0)
    button.titleEdgeInsets = UIEdgeInsets(top: 0, left: 16, bottom: 0, right: -16)
    button.setTitle(NSLocalizedString("SETTINGS", comment: ""), for: .normal)
    button.addTarget(self, action: #selector(backOnTapped), for: .touchUpInside)
    button.setTitleColor(.mainTextColor, for: .normal)
    button.titleLabel?.font = UIFont.systemFont(ofSize: 18.0)
    return button
  }()

2、左侧返回图标，标题居中

  public override func viewDidLoad() {
    
    ...
    navigationItem.titleView = titleView
    navigationController?.navigationBar.topItem?.backBarButtonItem = UIBarButtonItem(title: "", style: .plain, target: nil, action: nil)
    ...
  }
  
  private lazy var titleView: UILabel = {
    
    let label = UILabel()
    label.text = NSLocalizedString("Add Friend", comment: "Add friend")
    label.textColor = .mainTextColor
    label.font = .systemFont(ofSize: 18.0)
    return label
  }()