swift 2.0 与 OC 相比较，标签栏和导航栏书写的差别

 private func addChildViewControllers() {
        
        tabBar.tintColor = UIColor.orangeColor()
        zxaddChildViewController(HomeViewController(), title: "首页", imageName: "tabbar_home")
        zxaddChildViewController(MessageViewController(), title: "消息", imageName: "tabbar_message_center")
        zxaddChildViewController(DiscoverViewController(), title: "发现", imageName: "tabbar_discover")
        zxaddChildViewController(ProfileViewController(), title: "我", imageName: "tabbar_profile")
    
    }
    
    private func zxaddChildViewController(vc: UIViewController, title: String, imageName: String) {
       
        vc.title = title
        vc.tabBarItem.image = UIImage(named: imageName)
        addChildViewController(UINavigationController(rootViewController: vc))
        
    }

    HomeViewController * home =[[HomeViewController alloc]init];
    home.title=@"首页";
    home.tabBarItem.title=@"首页";
    UINavigationController * na = [[UINavigationController alloc]initWithRootViewController:home];

    HomeViewControllerone * home1 =[[HomeViewControllerone alloc]init];
    home1.title=@"首页1";
    home1.tabBarItem.title=@"首页2";
    UINavigationController * na1 = [[UINavigationController alloc]initWithRootViewController:home1];

    HomeViewControllertwo * home2 =[[HomeViewControllertwo alloc]init];
    home2.title=@"首页3";
    home2.tabBarItem.title=@"首页3";
    UINavigationController * na2 = [[UINavigationController alloc]initWithRootViewController:home2];

    
    HomeViewControllerT * home3 =[[HomeViewControllerT alloc]init];
    home3.title=@"首页4";
    home3.tabBarItem.title=@"首页4";
    UINavigationController * na3 = [[UINavigationController alloc]initWithRootViewController:home3];

    self.viewControllers=@[na,na1,na2,na3];