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 (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

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) } ...

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。

appearance()函数并不总是适用于我。所以我更喜欢创建一个NC对象并改变它的属性。

var navBarColor = navigationController!.navigationBar
navBarColor.barTintColor =
    UIColor(red:  255/255.0, green: 0/255.0, blue: 0/255.0, alpha: 100.0/100.0)
navBarColor.titleTextAttributes =
    [NSForegroundColorAttributeName: UIColor.whiteColor()]

此外，如果你想添加一个图像而不仅仅是文本，这也是可行的

var imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 70, height: 70))
imageView.contentMode = .ScaleAspectFit

var image = UIImage(named: "logo")
imageView.image = image
navigationItem.titleView = imageView

Swift 4, iOS 12和Xcode 10更新

只需在viewDidLoad()中放入一行

navigationController?.navigationBar.barTintColor = UIColor.red