public object Drawback() { try { bool temp = false; string piid = System.Web.HttpContext.Current.Request.Params["piid"] ?? string.Empty; WorkFlowExecutionContext ec = new WorkFlowExecutionContext(); ec.PiId = piid; ec.UserId = NG3.AppInfoBase.UserID.ToString(); service.ExecuteTaskRetrieve(ec, ec.UserId); temp = true; return(new JObject() { { "result", temp } }); } catch (Exception ex) { return(DCHelper.ErrorMessage(ex.Message)); } }