斯威夫特4:

在应用程序级别更改导航栏外观的完美代码。

// MARK: Navigation Bar Customisation

// To change background colour.
UINavigationBar.appearance().barTintColor = .init(red: 23.0/255, green: 197.0/255, blue: 157.0/255, alpha: 1.0)

// To change colour of tappable items.
UINavigationBar.appearance().tintColor = .white

// To apply textAttributes to title i.e. colour, font etc.
UINavigationBar.appearance().titleTextAttributes = [.foregroundColor : UIColor.white,
                                                    .font : UIFont.init(name: "AvenirNext-DemiBold", size: 22.0)!]
// To control navigation bar's translucency.
UINavigationBar.appearance().isTranslucent = false

编码快乐!

这里有一些非常基本的外观定制，你可以应用于整个应用程序:

UINavigationBar.appearance().backgroundColor = UIColor.greenColor()
UIBarButtonItem.appearance().tintColor = UIColor.magentaColor()
//Since iOS 7.0 UITextAttributeTextColor was replaced by NSForegroundColorAttributeName
UINavigationBar.appearance().titleTextAttributes = [UITextAttributeTextColor: UIColor.blueColor()]
UITabBar.appearance().backgroundColor = UIColor.yellowColor();

斯威夫特5.4.2:

UINavigationBar.appearance().backgroundColor = .green // backgorund color with gradient
// or
UINavigationBar.appearance().barTintColor = .green  // solid color
    
UIBarButtonItem.appearance().tintColor = .magenta
UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor : UIColor.blue]
UITabBar.appearance().barTintColor = .yellow

更多关于UIAppearance API在Swift你可以阅读这里。

Swift 5，一个简单的UINavigationController扩展方法。在这个答案的底部是扩展和预览。

第一个视图控制器(Home):

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    navigationController?.setTintColor(.white)
    navigationController?.backgroundColor(.orange)
}

第二个视图控制器(详细信息):

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    navigationController?.transparentNavigationBar()
    navigationController?.setTintColor(.black)
}

UINavigationController的扩展:

extension UINavigationController {
    func transparentNavigationBar() {
        self.navigationBar.setBackgroundImage(UIImage(), for: .default)
        self.navigationBar.shadowImage = UIImage()
        self.navigationBar.isTranslucent = true
    }

    func setTintColor(_ color: UIColor) {
        self.navigationBar.titleTextAttributes = [NSAttributedString.Key.foregroundColor: color]
        self.navigationBar.tintColor = color
    }

    func backgroundColor(_ color: UIColor) {
        navigationBar.setBackgroundImage(nil, for: .default)
        navigationBar.barTintColor = color
        navigationBar.shadowImage = UIImage()
    }
}

故事板视图:

预览:

Swift 5 (iOS 14)

全导航栏定制。

// -----------------------------------------------------------
// NAVIGATION BAR CUSTOMIZATION
// -----------------------------------------------------------
self.navigationController?.navigationBar.prefersLargeTitles = true
self.navigationController?.navigationBar.tintColor = UIColor.white
self.navigationController?.navigationBar.isTranslucent = false

if #available(iOS 13.0, *) {
    let appearance = UINavigationBarAppearance()
    appearance.configureWithDefaultBackground()
    appearance.backgroundColor = UIColor.blue
    appearance.largeTitleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
    appearance.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]

    navigationController?.navigationBar.standardAppearance = appearance
    navigationController?.navigationBar.scrollEdgeAppearance = appearance
    navigationController?.navigationBar.compactAppearance = appearance

} else {
    self.navigationController?.navigationBar.barTintColor = UIColor.blue
    self.navigationController?.navigationBar.largeTitleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
    self.navigationController?.navigationBar.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
}

// -----------------------------------------------------------
// NAVIGATION BAR SHADOW
// -----------------------------------------------------------
self.navigationController?.navigationBar.layer.masksToBounds = false
self.navigationController?.navigationBar.layer.shadowColor = UIColor.black.cgColor
self.navigationController?.navigationBar.layer.shadowOffset = CGSize(width: 0, height: 2)
self.navigationController?.navigationBar.layer.shadowRadius = 15
self.navigationController?.navigationBar.layer.shadowOpacity = 0.7

导航栏:

navigationController?.navigationBar.barTintColor = UIColor.green

用你想要的任何UIColor替换greenColor，如果你喜欢，你也可以使用RGB。

导航栏文本:

navigationController?.navigationBar.titleTextAttributes = [.foregroundColor: UIColor.orange]

用你喜欢的颜色替换orangeColor。

标签栏:

tabBarController?.tabBar.barTintColor = UIColor.brown

标签栏文本:

tabBarController?.tabBar.tintColor = UIColor.yellow

最后两个，用你选择的颜色替换brownColor和yellowColor。

首先将navigationBar的isTranslucent属性设置为false以获得所需的颜色。然后像这样改变导航栏的颜色:

@IBOutlet var NavigationBar: UINavigationBar!

NavigationBar.isTranslucent = false
NavigationBar.barTintColor = UIColor (red: 117/255, green: 23/255, blue: 49/255, alpha: 1.0)