{
   "errcode": 0,
   "errmsg": "ok",
   "department": [
       {
           "id": 2,
           "name": "广州研发中心",
           "parentid": 1
       },
       {
           "id": 3
           "name": "邮箱产品部",
           "parentid": 2
       }
   ]
}

    public class deptinfo
    {
        public string errcode = string.Empty;
        public string errmsg = string.Empty;
        public List<department> department = new List<department>();
    }

    public class department
    {
        public int id;
        public int parentid;
        public string name = string.Empty;
    }

   JavaScriptSerializer js = new JavaScriptSerializer();
   deptinfo info= js.Deserialize<deptinfo>(strResult);