ios - 如何在 ViewController 顶部设置标题

Question

在我的应用程序中，我有一个 tabBarViewController，这是第一个栏:

class FirstViewController: UIViewController {

  override func viewDidLoad() {
    super.viewDidLoad()
    view.backgroundColor = UIColor.white
  }

  override func viewWillAppear(_ animated: Bool) {
    self.navigationItem.title = "RECENTS"
  }

}

这是自定义类:

class CustomTabBar: UITabBarController {

  override func viewDidLoad() {
    super.viewDidLoad()

    let firstVC = FirstViewController()
    let secondVC = SecondViewController()
    let thirdVC = ThirdViewController()

    firstVC.tabBarItem.title = "RECENT"
    secondVC.tabBarItem.title = "MAP"
    thirdVC.tabBarItem.title = "SETTINGS"

    firstVC.title = "RECENT"
    secondVC.title = "MAP"
    thirdVC.title = "SETTINGS"

    viewControllers = [firstVC,secondVC,thirdVC]
  }

}

所以我的问题是:如何将标题放在 View Controller 的顶部？在之前的代码中我试过了，但它不起作用!

是这样的:

Answer 1

title 属性在 View Controller 包装在 UINavigationController 中时显示。这里有一些代码替换了你示例中的最后一行(即 viewControllers 分配)，应该可以解决问题:

let firstNC = UINavigationController(rootViewController: firstVC)
let secondNC = UINavigationController(rootViewController: secondVC)
let thirdNC = UINavigationController(rootViewController: thirdVC)
viewControllers = [firstNC,secondNC,thirdNC]