系统的，就是好。 解耦 性好。系统的 最稳定， 感觉。

老师的 真是 炫耀技巧， 造轮子。 效果还不好。 tabBar 之间 切换， 闪呀闪的。

老师造的轮子， 提供了 另一种 理解 的 思路， 理解系统 是 怎么实现的。

MainTabBarViewController

class MainTabBarViewController: UITabBarController {

    
    func createViewControllers(){
    
        
    
        
        let arrayNames = ["HomePageViewController","FindViewController","ChefViewController","FairViewController","ProfileViewController"]
        
        let names = ["首页","发现","","订单","我"]
        
        let imageNames = ["dock_home_unselected",
                          "dock_shop_unselected",
                          "custom_tabbar",
                          "dock_order_unselected",
                          "dock_self_unselected"]
        
        
        let selectedImageNames = ["dock_home_selected",
                                  "dock_shop_selected",
                                  "custom_tabbar",
                                  "dock_order_selected",
                                  "dock_self_selected"]
        
        
        var array = Array<UINavigationController>()
        
        
        for i in 0..<arrayNames.count{
        
            let controllerName = "deliciousOfCource." + arrayNames[i]
            
            let viewControllerClass = NSClassFromString(controllerName) as! UIViewController.Type
            
            let viewController = viewControllerClass.init()
            viewController.tabBarItem.title = names[i]
            viewController.tabBarItem.image = UIImage(named: imageNames[i])
            viewController.tabBarItem.selectedImage = UIImage(named: selectedImageNames[i])
            
            
            
            
            let navigationViewController = UINavigationController(rootViewController: viewController)
            
            
            array.append(navigationViewController)
            
            
            
            
        }
    
        self.viewControllers = array
    
        
    }
    
    
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        createViewControllers()
        
        self.tabBar.tintColor = UIColor.redColor()
    }

KTCHomeViewController

class KTCHomeViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }
    
    
    
    
    
    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        
        
        let appDelegation = UIApplication.sharedApplication().delegate as! AppDelegate
        let control = appDelegation.window?.rootViewController
        if control?.isKindOfClass(MainTabBarViewController.self) == true {
            let mainTabBarCtrl = control as! MainTabBarViewController
            mainTabBarCtrl.tabBar.hidden = false
        }
        
        
        
        
        
    }
    
    
    
    
    
        
    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        
        
        let appDelegation = UIApplication.sharedApplication().delegate as! AppDelegate
        let control = appDelegation.window?.rootViewController
        if control?.isKindOfClass(MainTabBarViewController.self) == true {
            let mainTabBarCtrl = control as! MainTabBarViewController
            mainTabBarCtrl.tabBar.hidden = false
        }
        
        
        
        
        
        
    }
        

        
    
    
    
    
    
    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
        
        
        let appDelegation = UIApplication.sharedApplication().delegate as! AppDelegate
        let control = appDelegation.window?.rootViewController
        if control?.isKindOfClass(MainTabBarViewController.self) == true {
            let mainTabBarCtrl = control as! MainTabBarViewController
            mainTabBarCtrl.tabBar.hidden = true
        }
        
        
        
        
        
        
        
        
        
    }