public IMember driver()
        {
            string assemblyName = ConfigurationManager.AppSettings["assembly"];//获取程序集名称
            string constructor = ConfigurationManager.AppSettings["constructor"];//获取默认构造器名称
            return (IMember)Assembly.Load(assemblyName).CreateInstance(constructor, false);
        }  <add key="Constructor" value="AccessDAL.DALMember" />
  <add key="assembly" value="AccessDAL" />
为什么会出现这种情况??????