<add key="Homepage" value="Training.HomePage"/>

public  class IMainFactory:IFactory
    {
      private static readonly string path = ConfigurationManager.AppSettings["Homepage"];
      private static readonly string className = path + ".MainPage";

        #region Interface Methods
        public Assembly CreateAssembly()
        {
            return Assembly.Load(path);
        }

        public IHomePage CreateMainPageInstance()
        {
            return (IHomePage)CreateAssembly().CreateInstance(className);
        }
        #endregion

     
    }
}

CreateMainPageInstance()方法
为什么返回的总是空对象呢？