如何设置.asmx webservice使用Asp.net启用跨域

My webservice code is

我的网络服务代码是

 [WebMethod]
     public List<test> GetMachineData_List(string prefix, int person_id)
     {
         using (var db = new TestDB())
         {
             List<test> list = db.Fetch<test>("select id,name from machine_data_collection mc where mc.id=@0 and name like '%" + prefix + "%'", person_id);
             return list.ToList();
         }
     }
 [WebMethod