AppDelegate.swift代码如下：

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        self.window = UIWindow(frame:UIScreen.main.bounds)
        self.window?.backgroundColor = UIColor.white
        self.window?.makeKeyAndVisible()
        //1.创建导航控制器的根视图
        let vc = ViewController()
        //2.创建导航视图控制器，并为他制定根视图控制器
        let navigation = UINavigationController(rootViewController: vc)
        //3.将导航视图控制器设置为window的根视图控制器
        self.window?.rootViewController = navigation


        return true
    }

ViewController.swift代码如下：

import UIKit

class ViewController: UIViewController {
    override func viewWillAppear(_ animated: Bool) {
        self.navigationController?.isNavigationBarHidden = false
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        self.setupNavigationBar()
    }
    func setupNavigationBar() {
        //UINavigationController 配置他的时候设置只是当前视图控制器上导航条外观
//        self.title = "拨号"
        self.navigationItem.title = "消息"
        //设置title颜色字体
        let dic = [NSFontAttributeName:UIFont.systemFont(ofSize: 30.0),NSForegroundColorAttributeName:UIColor.red]

        self.navigationController?.navigationBar.titleTextAttributes = dic
        //创建按钮对象
        let rightButton = UIBarButtonItem(title: "跳转", style: .plain, target: self, action: #selector(rightButtonAction))
        //给右侧rightBarButtonItem赋值
        self.navigationItem.rightBarButtonItem = rightButton
        //配置左侧的leftBarButtonItem
        self.navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .action, target: self, action: #selector(leftButtonAction))

        //UINavigationBar 配置他的时候所有视图都会显示,公共的属性，此时是通过导航视图控制器来设置
        self.navigationController?.isNavigationBarHidden = false
        //bar颜色
//        self.navigationController?.navigationBar.barStyle = .black
        //bar背景颜色
        self.navigationController?.navigationBar.backgroundColor = #colorLiteral(red: 0.721568644, green: 0.8862745166, blue: 0.5921568871, alpha: 1)
        //导航条yans
        self.navigationController?.navigationBar.barTintColor = UIColor.yellow
        //设置控件颜色
        self.navigationController?.navigationBar.tintColor = UIColor.black
    }
    //设置leftButtonAction的关联方法
    func leftButtonAction() {
        print("左侧按钮")
    }
    //设置rightButtonAction的关联方法
    func rightButtonAction() {
        let redVC = RedViewController()
        self.navigationController?.pushViewController(redVC, animated: true)

    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

RedViewController.swift代码如下：

import UIKit

class RedViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        self.view.backgroundColor = #colorLiteral(red: 0.9568627477, green: 0.6588235497, blue: 0.5450980663, alpha: 1)
        self.setupNavigationBar()
//        self.navigationController?.isNavigationBarHidden = true
        //导航条的毛玻璃效果，半透明效果
        //导航栏半透明效果(IOS7以后 默认YES)
        //当半透明效果开启时 屏幕左上角为坐标原点
        //关闭时，导航栏左下角为坐标原点
        self.navigationController?.navigationBar.isTranslucent = false
        let button = UIButton(type: .custom)
        button.frame = CGRect(x: 0, y: 0, width: 150, height: 100)
        button.backgroundColor = #colorLiteral(red: 0.8039215803, green: 0.8039215803, blue: 0.8039215803, alpha: 1)
        button.setTitle("返回", for: .normal)
        self.view.addSubview(button)

        button.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)

    }
    //button关联事件
    func buttonAction(){
        self.navigationController?.isNavigationBarHidden = false
        self.navigationController?.popViewController(animated: true)
    }
    func setupNavigationBar() {
        let left1 = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(leftAction))
        let left2 = UIBarButtonItem(barButtonSystemItem: .camera,target:self, action:#selector(left2Action))
        self.navigationItem.leftBarButtonItems = [left1,left2]

        let titleView = UISegmentedControl(items: ["消息","电话"])
        titleView.frame = CGRect(x:0,y:0,width:100,height:30)
        titleView.selectedSegmentIndex = 0
        //给navigationItem和titleView属性赋值
        self.navigationItem.titleView = titleView




    }
    //left的关联方法
    func leftAction(sender:UIBarButtonItem) {
        self.navigationController?.popViewController(animated: true)

    }
    //left2的关联方法
    func left2Action(sender:UIBarButtonItem) {

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}