一、封装方法 创建子控制器

    //调用封装方法
    addChildViewController(LXRHomeViewController(), title: "首页", imageName: "tabbar_home")
    addChildViewController(LXRMessageViewController(), title: "消息", imageName: "tabbar_message_center")
    addChildViewController(LXRDiscoverViewController(), title: "发现", imageName: "tabbar_discover")
    addChildViewController(LXRProfileViewController(), title: "我", imageName: "tabbar_profile")

    // Swift支持方法的重改:方法名称相同.但是参数类型和个数不同
    // private在当前文件中可以访问,其他文件不能访问
    // swift3.0 private建议修改为fileprivate
    private func addChildViewController(_ childVc: UIViewController, title : String, imageName : String) {
        //1.设置自控制器的属性
        childVc.title = title
        childVc.tabBarItem.image = UIImage(named: imageName)
        childVc.tabBarItem.selectedImage = UIImage(named: imageName + "_highlighted")
        //2.包装导航控制器
        let childNav = UINavigationController(rootViewController: childVc)
        //3.添加控制器
        addChildViewController(childNav)
    }

二、根据Json文件,通过字符串获取数据

创建MainVCSettings.json的json文件，并导入项目中，文件内容如下：

    [
     {
        "vcName": "HomeViewController",
        "title": "首页",
        "imageName": "tabbar_home"
     },
     {
         "vcName": "MessageViewController",
         "title": "消息",
         "imageName": "tabbar_message_center"
     },
     {
         "vcName": "DiscoverViewController",
         "title": "广场",
         "imageName": "tabbar_discover"
     },
     {
         "vcName": "ProfileViewController",
         "title": "我",
         "imageName": "tabbar_profile"
     }
     ]

获取不到文件路径请按照这篇文章配置下
http://www.jianshu.com/p/db888332206a

    //1.获取JSON文件路径
    guard let jsonPath = Bundle.main.path(forResource: "MainVCSettings.json", ofType: nil) else {
        LXRLog(message: "没有获取到对应的文件路径")
        return
    }
    //2.读取json文件中的内容
    guard let jsonData = try? Data(contentsOf: URL(fileURLWithPath: jsonPath)) else {
        LXRLog(message: "没有获取到json文件中数据")
        return
    }
    //3.将Data转成数组
    guard  let anyObject = try? JSONSerialization.jsonObject(with: jsonData, options: .mutableContainers) else {
        return
    }

    guard let dictArray = anyObject as? [[String : AnyObject]] else{
        return
    }
    //4.遍历字典,获取对应的信息
    for dict in dictArray{
        //4.1获取控制器的对应的字符串
        guard let VcName = dict["vcName"] as? String else {
            continue
        }
        //4.2获取控制器显示的title
        guard let title = dict["title"] as? String else {
            continue
        }
        //4.3获取控制器显示的图标名称
        guard let imageName = dict["imageName"] as? String else {
            continue
        }
        //4.4添加自控制器
        addChildViewController(VcName, title: title, imageName: imageName)
    }

    /**************************************************/

    // Swift支持方法的重改:方法名称相同.但是参数类型和个数不同
    // private在当前文件中可以访问,其他文件不能访问

    private func addChildViewController(_ childVcName: String, title : String, imageName : String) {
        
        //0.获得命名空间
        guard let nameSpace = (Bundle.main.infoDictionary!["CFBundleExecutable"] as? String)  else {
            LXRLog(message: "没有获取命名空间")
            return
        }
        //1.根据字符创获取对应的Class
        guard let ChildVcClass = NSClassFromString(nameSpace + "." + childVcName)  else {
            LXRLog(message: "没有获取到字符创对应的Class")
            return
        }
        // 2.将对应的AnyObject转成控制器的类型
        guard let childVcType = ChildVcClass as? UIViewController.Type else {
            LXRLog(message: "没有获取对应控制器的类型")
            return
        }
        // 3.创建对应的控制器对象
        let childVc = childVcType.init()
        
        //4.设置自控制器的属性
        childVc.title = title
        childVc.tabBarItem.image = UIImage(named: imageName)
        childVc.tabBarItem.selectedImage = UIImage(named: imageName + "_highlighted")
        //5.包装导航控制器
        let childNav = UINavigationController(rootViewController: childVc)
        //6.添加控制器
        addChildViewController(childNav)
    }