从 TableView 推送视图控制器后如何保持导航栏标题较大

How to keep navigation bar title large after pushing view controller from TableView

I have a tableview displaying on a main view controller, and when a row is selected a detail view controller is pushed.我有一个主视图控制器的大标题,以及详细视图控制器的 small/regular 标题。它们嵌入在导航控制器和标签栏控制器中。

Before selecting a row, the main view controller title is large, and when a row is selected the detail view controller title is regular as it should be.但是当我从详细视图控制器 return 到主视图控制器时(通过 "back" 按钮),主视图控制器上的标题不再大。

我在主视图控制器上将 "prefersLargeTitles" 设置为 true,在详细视图控制器上将 "largeTitleDisplayMode" 设置为从不。

我尝试将 "largeTitleDisplayMode" 设置为始终在主视图控制器上,但无济于事。我也试过在任一视图控制器上将其设置为自动,但似乎没有效果。

我也尝试过使用 "viewWillAppear" 和 "viewWillDisappear" 并在其中设置标题,虽然它确实将主视图控制器标题重置为大标题,但动画滞后并且不是从小标题过渡到大标题时不像往常那样流畅。

此外,我对编码还很陌生,这是我在不使用故事板的情况下构建的第一个应用程序,因此代码可能会一团糟。

主视图控制器代码:

class HomeViewController: UIViewController {

  let tableView = UITableView()

  override func loadView() {
      super.loadView()
      view.backgroundColor = .white
      self.title = "Home"

      // Set large title
      navigationController?.navigationBar.prefersLargeTitles = true


      // Make navigation bar transparent
      navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default)
      navigationController?.navigationBar.shadowImage = UIImage()
      navigationController?.navigationBar.isTranslucent = true


}


extension HomeViewController: UITableViewDelegate {

  func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

      let vc = DetailViewController() as DetailViewController

      if indexPath.section == 0 {
          vc.detailTitle = itemsTop[indexPath.row]
      } else if indexPath.section == 1 {
          vc.detailTitle = itemsBottom[indexPath.row]
      } else {
          print("Failed to load title")
      }


      navigationController?.pushViewController(vc, animated: true)

      tableView.deselectRow(at: indexPath, animated: true)
  }

}

详细视图控制器代码:

class DetailViewController: UIViewController {

  var detailTitle: String?

  override func viewDidLoad() {
      super.viewDidLoad()

      title = detailTitle

      // Make nav bar transparent
      navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default)
      navigationController?.navigationBar.shadowImage = UIImage()
      navigationController?.navigationBar.isTranslucent = true

      // Prevent large title
      navigationController?.navigationBar.prefersLargeTitles = false
  }

}

您需要在主视图控制器的 viewWillAppear 中将 navigationController?.navigationBar.prefersLargeTitles 设置为 true,以便每次返回主视图控制器时都让它 运行 。

您可以在 viewWillAppear 的详细信息中将其设置为 false,并在 viewWillDisappear 的详细信息中将其还原,以防止它也保持为 false。

您的 DetailVC 的代码:

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    navigationController?.navigationBar.prefersLargeTitles = false
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    navigationController?.navigationBar.prefersLargeTitles = true
}

try this it's working. In 'HomeViewController'

override func viewDidLoad() {
    super.viewDidLoad()

    navigationController?.navigationBar.prefersLargeTitles = true
}

In 'DetailViewController'

override func viewDidLoad() {
    super.viewDidLoad()

    self.navigationItem.largeTitleDisplayMode = .never
}