【Swift】通过类名创建对象

import Foundationimport UIKitextension NSObject {   func swiftClassFromString(className: String) -> UIViewController! {        // get the project name        if  let appName: String = NSBundle.mainBundle().objectForInfoDictionaryKey("CFBundleName") as! String? {            //拼接控制器名            let classStringName = "\(appName).\(className)"            //将控制名转换为类            let classType = NSClassFromString(classStringName) as? UIViewController.Type            if let type = classType {                let newVC = type.init()                return newVC            }        }        return nil;    }}  //将控制器名转换为类        let vc = self.swiftClassFromString(className)        self.navigationController！.pushViewController(vc, animated: true)