使用plist文件來加載控制器以及圖片文字等資源

func setup() {
        UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName: UIColor(red:56/255.0, green:165/255.0, blue:241/255.0, alpha:1)], forState: .Selected)
        UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName: UIColor(red:132/255.0, green:132/255.0, blue:132/255.0, alpha:1)], forState: .Normal)
        self.tabBar.backgroundImage = UIImage(named: "tabbar_back")
        
        let path = NSBundle.mainBundle().pathForResource("YWTabBarViewController", ofType: "plist")
        let array = NSArray(contentsOfFile: path!)

        if array != nil {
            for dic in array! {
                //將類名轉(zhuǎn)化為類
                //1.獲取命名空間
                let clsName = NSBundle.mainBundle().infoDictionary!["CFBundleExecutable"] as! String
                
                let forDic = dic as! NSDictionary
                //2.把字符串形式的類名稱轉(zhuǎn)換成類
                let classType = NSClassFromString(clsName + "." + "\(forDic["viewController"]!)") as! UIViewController.Type
                //3.通過class創(chuàng)建對象
                let vc = classType.init()
     
                vc.tabBarItem.image = UIImage(named: "\(forDic["image"]!)")
                vc.tabBarItem.selectedImage = UIImage(named: "\(forDic["selectImage"]!)")
                vc.tabBarItem.title = "\(forDic["title"]!)"
                addChildViewController(vc)
            }
        }

    }