代码创建UINavigationController

首先，需要在项目设置去掉 Main Interface

在代码中自定义UIWindow对象，并设置控制器，注意，我这里用到的控制器都在关联了xib的

//
//  AppDelegate.swift
//  代码创建导航
//
//  Created by zhang on 16/1/16.
//  Copyright © 2016年 jin. All rights reserved.
//

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


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

        // 先取消项目设置中的 Main Interface
        // 初始化窗口对象
        let window = UIWindow()

        // 初始化 navigation 对象
        // 初始化默认显示的控制器
        let mainController = UIViewControllerA()

        // 初始化 navigation
        // 这种方式设置初始化需要后面设置下默认控制器
//        let navigation = UINavigationController()
        // 在初始化的时候指定默认控制器
        let navigation = UINavigationController(rootViewController: mainController)

        // 下面的是两种设置 navigation 默认控制器的方法
//        navigation.addChildViewController(mainController)
//        navigation.pushViewController(mainController, animated: true)

        // 设置当前窗口的根控制器
        window.rootViewController = navigation

        self.window = window
        // 当前窗口作为主窗口并显示
        self.window?.makeKeyAndVisible()
        return true
    }
}

navigation的根控制器

//
//  UIViewControllerA.swift
//  代码创建导航
//
//  Created by zhang on 16/1/16.
//  Copyright © 2016年 jin. All rights reserved.
//

import UIKit

class UIViewControllerA: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // 设置导航栏标题
        self.title = "第一个控制器"

        // 导航条左边的按钮
        let addButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Add, target: nil, action: nil)
        let cameraButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Camera, target: nil, action: nil)
        // 赋值
        self.navigationItem.leftBarButtonItems = [addButton,cameraButton]

        // 设置导航栏右边的按钮
        let composeButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Compose, target: nil, action: nil)
        let actionButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Action, target: nil, action: nil)
        self.navigationItem.rightBarButtonItems = [composeButton,actionButton]


        // 设置返回
        let backButton = UIBarButtonItem(title: "返回", style: UIBarButtonItemStyle.Plain, target: nil, action: nil)

        self.navigationItem.backBarButtonItem = backButton
        // Do any additional setup after loading the view.
    }

    @IBAction func nextController(sender: UIButton) {
//        let controller = UIViewControllerB(nibName: "UIViewControllerB", bundle : nil)
        let controller = UIViewControllerB()
        // 把下个控制器对象加入 navigation 的栈，因为navigavtion会显示栈顶的控制器，所以，相当于跳转到下个控制器
        self.navigationController?.pushViewController(controller, animated: true)
    }
}

第二个控制器

//
//  UIViewControllerB.swift
//  代码创建导航
//
//  Created by zhang on 16/1/16.
//  Copyright © 2016年 jin. All rights reserved.
//

import UIKit

class UIViewControllerB: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        self.navigationItem.title = "第二个控制器"

        // Do any additional setup after loading the view.
    }
    // 返回
    @IBAction func back(sender: AnyObject) {
        // 移除当前控制器，回到上一个，相当于返回
        self.navigationController?.popViewControllerAnimated(true)
    }
    // 跳转到下个controller
    @IBAction func next(sender: AnyObject) {
        let controller = UIViewControllerC()
        self.navigationController?.pushViewController(controller, animated: true)
    }
}

第三个控制器

//
//  UIViewControllerC.swift
//  代码创建导航
//
//  Created by zhang on 16/1/16.
//  Copyright © 2016年 jin. All rights reserved.
//

import UIKit

class UIViewControllerC: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        self.title = "第三个控制器"
        // 这只 item titleview
        self.navigationItem.titleView = UIImageView(image: UIImage(imageLiteral: "1"))
        // Do any additional setup after loading the view.
    }
    @IBAction func back(sender: AnyObject) {
        // 回到上一个控制器
        self.navigationController?.popViewControllerAnimated(true)
    }

    @IBAction func backRoot(sender: AnyObject) {
        // 回到根控制器
        self.navigationController?.popToRootViewControllerAnimated(true)
    }
}