反射机制

在Swift中并不提倡使用Runtime，而是像其他语言一样使用反射(Reflect)。当然，目前Swift中的反射还没有其他语言中的反射功能强大，不仅远不及OC的Runtime，离Java的反射也有一定的距离。
Swift的反射机制是基于一个叫 Mirror 的 struct 来实现的

//反射事例

    //反射机制，取出类的名字，转换成类，还要强转成类的类型
       
        //1.从Bundle取出项目的名字（命名空间 = “项目的名字”+“.”+"类名"）
        //2.修改命名空间，TARGETS -> Build Setting -> 输入product name ->修改即可
         print("\(Bundle.main.infoDictionary)")
        let clsN = Bundle.main.infoDictionary?["CFBundleName"] as? String ?? ""
        
        //3.let class NSClassFromString(className) as? class.Type
        //4. let cls = class?.init()
        let clsName = clsN + ".ViewController"
        let cls = NSClassFromString(clsName) as? ViewController.Type
        let vc = cls?.init()
        window?.rootViewController = vc
//        let vc = ViewController()
//        window?.rootViewController = vc
        window?.makeKeyAndVisible()
//2.//MARK:添加子控制器
    //反射机制，将控制器的属性添加到字典数组中,然后再创建一个存储有控制器的数组A，遍历存储有控制器所有属性的数组，并调用返回控制器的方法，添加到数组A中，并把数组赋值给viewControllers//----反射控制器的方法
    //根据命名空间+"."+"类名"反射出类
    //再设置类的title,image,文字大小 
    //再创建导航将根控制器添加上去，返回导航
    func setupChildViewController (){
        let array = [["clsName":"SinaHomeViewController","title":"首页","imageName":"tabbar_home"],["clsName":"SinaHomeViewController","title":"信息","imageName":"tabbar_message_center"],
             ["clsName":"","title":"","imageName":""],
            ["clsName":"SinaHomeViewController","title":"发现","imageName":"tabbar_discover"],["clsName":"SinaHomeViewController","title":"我","imageName":"tabbar_profile"]]
        
        var arrayVc = [UIViewController]()
        for dict in array{
            arrayVc.append(addViewController(dict: dict))
        }
        viewControllers = arrayVc
    }
    
   func addViewController(dict:[String:String])-> UIViewController{
        //判断字典中是否有title,类名，imageName
        guard let clsName = dict["clsName"],
             let title = dict["title"],
             let imageName = dict["imageName"],
             let cls = NSClassFromString(Bundle.main.nameSpace + "." + clsName) as? UIViewController.Type else{
          return UIViewController()
        }
        let vc = cls.init()
        vc.title = title
        vc.tabBarItem.image = UIImage(named: imageName)
        vc.tabBarItem.selectedImage = UIImage(named: imageName + "_selected")?.withRenderingMode(.alwaysOriginal)
        vc.tabBarItem.setTitleTextAttributes([NSForegroundColorAttributeName:UIColor.black], for: .normal)
        let nav = SinaNavController(rootViewController: vc)
        return nav
    }

 

来源：https://www.cnblogs.com/TheYouth/p/6435546.html