iOS 8 (swift)

let font: UIFont = UIFont(name: "fontName", size: 17)   
let color = UIColor.backColor()
self.navigationController?.navigationBar.topItem?.backBarButtonItem?.setTitleTextAttributes([NSFontAttributeName: font,NSForegroundColorAttributeName: color], forState: .Normal)

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:

UINavigationBar.appearance().barTintColor = UIColor(red: 46.0/255.0, green: 14.0/255.0, blue: 74.0/255.0, alpha: 1.0)
UINavigationBar.appearance().tintColor = UIColor.whiteColor()
UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName : UIColor.whiteColor()]

只需将这一行粘贴到代码中的didFinishLaunchingWithOptions中。

在AppDelegate中，这已经全局地改变了导航栏的格式，并删除了底线/边界(这对大多数人来说是一个问题区域)，给你我认为你和其他人正在寻找的东西:

 func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    UINavigationBar.appearance().setBackgroundImage(UIImage(), forBarPosition: UIBarPosition.Any, barMetrics: UIBarMetrics.Default)
    UINavigationBar.appearance().shadowImage = UIImage()
    UINavigationBar.appearance().tintColor = UIColor.whiteColor()
    UINavigationBar.appearance().barTintColor = Style.SELECTED_COLOR
    UINavigationBar.appearance().translucent = false
    UINavigationBar.appearance().clipsToBounds = false
    UINavigationBar.appearance().backgroundColor = Style.SELECTED_COLOR
    UINavigationBar.appearance().titleTextAttributes = [NSFontAttributeName : (UIFont(name: "FONT NAME", size: 18))!, NSForegroundColorAttributeName: UIColor.whiteColor()] }

然后你可以设置一个Constants.swift文件，其中包含一个带有颜色和字体等的样式结构。然后你可以添加一个tableView/pickerView到任何ViewController，并使用“availableThemes”数组允许用户改变themeColor。

关于这一点的美妙之处在于，你可以在整个应用程序中为每种颜色使用一个引用，它会根据用户选择的“主题”进行更新，如果没有一个，它默认为theme1():

import Foundation
import UIKit

struct Style {


static let availableThemes = ["Theme 1","Theme 2","Theme 3"]

static func loadTheme(){
    let defaults = NSUserDefaults.standardUserDefaults()
    if let name = defaults.stringForKey("Theme"){
        // Select the Theme
        if name == availableThemes[0]   { theme1()  }
        if name == availableThemes[1]   { theme2()  }
        if name == availableThemes[2]   { theme3()  }
    }else{
        defaults.setObject(availableThemes[0], forKey: "Theme")
        theme1()
    }
}

 // Colors specific to theme - can include multiple colours here for each one
static func theme1(){
   static var SELECTED_COLOR = UIColor(red:70/255, green: 38/255, blue: 92/255, alpha: 1) }

static func theme2(){
    static var SELECTED_COLOR = UIColor(red:255/255, green: 255/255, blue: 255/255, alpha: 1) }

static func theme3(){
    static var SELECTED_COLOR = UIColor(red:90/255, green: 50/255, blue: 120/255, alpha: 1) } ...

我必须这么做

UINavigationBar.appearance().tintColor = UIColor.whiteColor()
UINavigationBar.appearance().barStyle = .Black
UINavigationBar.appearance().backgroundColor = UIColor.blueColor()

否则背景颜色不会改变

iOs 14 +

init() {        
    let appearance = UINavigationBarAppearance()
    appearance.shadowColor = .clear // gets also rid of the bottom border of the navigation bar
    appearance.configureWithTransparentBackground() 
    UINavigationBar.appearance().standardAppearance = appearance
    UINavigationBar.appearance().scrollEdgeAppearance = appearance
}