swift 3.0 -UINavigationController

//  AppDelegate.swift
//  swift-UINavigationController 导航控制器
//
//  Created by yidong on 16/9/30.
//  Copyright © 2016年 东哥. All rights reserved.
//

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)
        
        // Override point for customization after application launch.
        
        self.window!.backgroundColor = UIColor.white
        
        self.window!.makeKeyAndVisible()
        
        //定义一个视图控制器
        
        let one_vc = OneViewController(nibName:nil,bundle: nil);
        
        //创建导航控制器
        
        let nvc=UINavigationController(rootViewController:one_vc);
        
        //设置根视图
        
        self.window!.rootViewController=nvc;
        
        
        
        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    }

    func applicationWillTerminate(_ application: UIApplication) {
        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    }


}

import UIKit

class OneViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

       self.title = "第一个"
        
        //Swift 3 之后写法由"next" 改为#selector(OneViewController.clickNext)
        
       let nextItem = UIBarButtonItem(title:"点击",style:UIBarButtonItemStyle.plain,target:self,action:#selector(OneViewController.clickNext))//函数放在viewDidLoad外
        
        
      self.navigationItem.rightBarButtonItem = nextItem
        
        
        
        
    }

    func clickNext()
        
    {
        
        // 定义一个控制器
        
        let tow_vc = TowViewController();
        
        //推入下一个视图 Swift 3 之后self.navigationController后加？
        
        self.navigationController?.pushViewController(tow_vc,animated:true);
        
    }
    


}

import UIKit

class TowViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        self.title="第二个";
        
        let  but=UIButton(frame:CGRect(x:110,y:100,width:100,height:40)) ;
    
        
        but.tag=1001;
        
        //设置标题
        but.setTitle("上一页", for: UIControlState.normal)
        
        
        but.addTarget(self,action:#selector(TowViewController.butClick(but:)),for:UIControlEvents.touchUpInside)
        but.backgroundColor=UIColor.blue
        
        self.view.addSubview(but)
        
        
        let but1=UIButton(frame:CGRect(x:110,y:200,width:100,height:40)) ;
    
        
        but1.tag=1002;
        
        //设置标题
        
        but1.setTitle("下一页",for:UIControlState.normal);
        
        //添加事件
        
    but1.addTarget(self,action:#selector(TowViewController.butClick(but:)),for:UIControlEvents.touchUpInside);
        
        but1.backgroundColor=UIColor.blue;
        
        self.view.addSubview(but1);
        
        
    let myItem=UIBarButtonItem(barButtonSystemItem:UIBarButtonSystemItem.action,target:self,action:#selector(TowViewController.ItemClick));
        
        self.navigationItem.leftBarButtonItem=myItem;

    }

    
    func butClick(but:UIButton)
        
    {
        
        
        switch (but.tag)
            
        {
            
        case 1001:
            
    _ = self.navigationController?.popViewController(animated:true)
            
        case 1002:
            
            let three = ThreeViewController();
            
            self.navigationController?.pushViewController(three,animated:true);
            
        default:
            
            print("null");
            
        }
        
    }
    
    func ItemClick()
        
    {
        
        let  label=UILabel(frame:CGRect(x:20,y:300,width:280,height:50));
        
        label.text="傻吊"
        
        self.view.addSubview(label);
        
        
    }

}