导航栏标题未显示

Question

我以编程方式添加了NavigationBar，然后添加了标题，但它根本没有出现。这里的问题是什么?

let navigationBar = UINavigationBar(frame: CGRectMake(0, 0, self.view.frame.size.width, 55))
navigationBar.barTintColor = UIColor(red: 44/255, green: 54/255, blue: 63/255, alpha: 1)
navigationController?.navigationItem.title = "AAA"
UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName : UIColor.whiteColor()]
view.addSubview(navigationBar)

出现了

navigationBar，但没有标题。如何解决这个问题?

我也试过了:

navigationBar.topItem?.title = "BBB"

没有再次

Answer 1

希望这对你有帮助。

// Create the navigation bar
let navigationBar = UINavigationBar(frame: CGRectMake(0, 0, self.view.frame.size.width, 64)) 
// Offset by 20 pixels vertically to take the status bar into account
navigationBar.backgroundColor = UIColor.whiteColor()
// Create a navigation item with a title
let navigationItem = UINavigationItem()
    navigationItem.title = "Title"
// Assign the navigation item to the navigation bar
navigationBar.items = [navigationItem]
// Make the navigation bar a subview of the current view controller
self.view.addSubview(navigationBar)

这个代码是为我工作。

UPDATE: Swift 4/Swift 5

// Create the navigation bar
let navigationBar = UINavigationBar(frame: CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: 64))
// Offset by 20 pixels vertically to take the status bar into account
navigationBar.backgroundColor = UIColor.white
// Create a navigation item with a title
let navigationItem = UINavigationItem()
navigationItem.title = "Title"
// Assign the navigation item to the navigation bar
navigationBar.items = [navigationItem]
// Make the navigation bar a subview of the current view controller
self.view.addSubview(navigationBar)

Answer 2

在被显示的视图控制器中设置导航栏标题。通常这是在视图控制器上的viewdidload中完成的:

override func viewDidLoad() {
    super.viewDidLoad()
    self.title = "AAA"
}

EDIT:在意识到OP将UINavigationBar添加到UIViewController而不是使用标准UINavigationController后:

let navigationBar = UINavigationBar(frame: CGRectMake(0, 0, self.view.frame.size.width, 55))
navigationBar.barTintColor = UIColor(red: 44/255, green: 54/255, blue: 63/255, alpha: 1)
let navigationItem = UINavigationItem.init(title: "AAA")
navigationBar.items = [navigationItem]
view.addSubview(navigationBar)