如何在Xcode中左对齐导航栏的标题？

Question

我一直在尝试以下操作，以使导航栏的标题保持对齐：

在AppDelegate.swift文件中：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.


    UINavigationBar.appearance().barTintColor = UIColor.red
    UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName:
        UIColor.white]
    return true
}

在TableViewController.swift文件中：

override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        self.navigationController?.navigationBar.topItem?.title = "Home"
    }

但我找不到解决问题的方法。我还尝试了以下在此处未显示任何内容的内容：

在AppDelegate.swift文件中：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.


    UINavigationBar.appearance().barTintColor = UIColor.red
    UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName:
        UIColor.white]
let lbNavTitle = UILabel (frame: CGRect(x: 0, y: 40, width: 320, height: 40))
    lbNavTitle.center = CGPoint(x: 160, y: 285)
    lbNavTitle.textAlignment = .left
    lbNavTitle.text = "Home"
    self.navigationItem.titleView = lbNavTitle

在TableViewController.swift文件中：

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    self.navigationController?.navigationBar.topItem?.title = "Home"
    let lbNavTitle = UILabel (frame: CGRect(x: 0, y: 0, width: 320, height: 40))
    lbNavTitle.backgroundColor = UIColor.red
    lbNavTitle.textColor = UIColor.black
    lbNavTitle.numberOfLines = 0
    lbNavTitle.center = CGPoint(x: 0, y: 0)
    lbNavTitle.textAlignment = .left
    lbNavTitle.text = "Home"

    let string = NSMutableAttributedString ("Title/nSubTitle")

    self.navigationItem.titleView = lbNavTitle
}

Answer 1

您可以使用navigationItems titleView添加具有左对齐的UILabel，然后使用自动布局设置其框架，如下所示：

let label = UILabel()
label.text = "Title Label"
label.textAlignment = .left
self.navigationItem.titleView = label
label.translatesAutoresizingMaskIntoConstraints = false
label.superview?.addConstraint(NSLayoutConstraint(item: label, attribute: .centerX, relatedBy: .equal, toItem: label.superview, attribute: .centerX, multiplier: 1, constant: 0))
label.superview?.addConstraint(NSLayoutConstraint(item: label, attribute: .width, relatedBy: .equal, toItem: label.superview, attribute: .width, multiplier: 1, constant: 0))
label.superview?.addConstraint(NSLayoutConstraint(item: label, attribute: .centerY, relatedBy: .equal, toItem: label.superview, attribute: .centerY, multiplier: 1, constant: 0))
label.superview?.addConstraint(NSLayoutConstraint(item: label, attribute: .height, relatedBy: .equal, toItem: label.superview, attribute: .height, multiplier: 1, constant: 0))