step1：自定义一个类  NTViewController，该类继承UITabBarController：

//
//  NTViewController.swift
//  Housekeeper
//
//  Created by 卢洋 on 15/10/20.
//  Copyright © 2015年 奈文摩尔. All rights reserved.
//

import Foundation
import UIKit
class NTViewController:UITabBarController{
   
    var items=[];
    //页面初始化
    override func viewDidLoad() {
        super.viewDidLoad();
        //1.创建首页导航控制器
        let vwIndex=index();
        let navIndex=UINavigationController(rootViewController: vwIndex);
        navIndex.title="首页";
　　　　　//设置工具栏默认显示的图片
        navIndex.tabBarItem.image=UIImage(named: "home")?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
　　　　　//设置工具栏选中后的图片
        navIndex.tabBarItem.selectedImage=UIImage(named: "homes.png")?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
        
        
        //2.创建活动信息导航控制器
        let vwActivityInfo=activityInfo();
        let navActivityInfo=UINavigationController(rootViewController: vwActivityInfo);
        navActivityInfo.title="活动信息";
        navActivityInfo.tabBarItem.image=UIImage(named: "Activity-information.png")?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
        navActivityInfo.tabBarItem.selectedImage=UIImage(named: "Activity-informations.png")?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
        
        
        //3.创建车辆展示导航控制器
        let vwCarDisplay=carDisplay();
        let navCarDisplay=UINavigationController(rootViewController: vwCarDisplay);
        navCarDisplay.title="车辆展示";
        navCarDisplay.tabBarItem.image=UIImage(named: "Vehicle-display.png")?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
        navCarDisplay.tabBarItem.selectedImage=UIImage(named: "Vehicle-displays.png")?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);

        
        //4.创建个人中心导航控制器
        let vwPersonalCenter=personalCenter();
        let navPersonalCenter=UINavigationController(rootViewController: vwPersonalCenter);
        navPersonalCenter.title="个人中心";
        navPersonalCenter.tabBarItem.image=UIImage(named: "Personal-Center.png")?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
        navPersonalCenter.tabBarItem.selectedImage=UIImage(named: "Personal-Centers.png")?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);

        
        //5.添加到工具栏
         items=[navIndex,navActivityInfo,navCarDisplay,navPersonalCenter];
        self.viewControllers=items as? [UIViewController];
        self.navigationController?.navigationBar.tintColor=UIColor.whiteColor();
        
        //6.自定义工具栏
        self.tabBar.backgroundColor=UIColor.clearColor();
        //底部工具栏背景颜色
        self.tabBar.barTintColor=UIColor.appMainColor();
        
        //7.设置底部工具栏文字颜色（默认状态和选中状态）
        UITabBarItem.appearance().setTitleTextAttributes(NSDictionary(object:UIColor.whiteColor(), forKey:NSForegroundColorAttributeName) as? [String : AnyObject], forState:UIControlState.Normal);
        UITabBarItem.appearance().setTitleTextAttributes(NSDictionary(object:UIColor.blueWithTabbar(), forKey:NSForegroundColorAttributeName) as? [String : AnyObject], forState:UIControlState.Selected)
        
    }

}

step2:打开 AppDelegate.swift

//
//  AppDelegate.swift
//  Housekeeper
//