public bool DeleteUnit(string unitid, string operateip, string operateid)
 {
     var dal = new ProductsDAL();
     bool bl = dal.UpdateUnitStatus(unitid, (int)EnumStatus.Delete);
     if (bl)
     {
         var model = GetUnitByID(unitid);
         CacheUnits.Remove(model);
     }
     return bl;
 }