How can I add subtotal to the bottom of the data entry or inquiry grids?

Hi @aaghaei, 
I recently came through a similar project to have totals as a separate row on various different project screens/tabs. 
You will have to extend your base graph and add/modify the underlying view for the grid. For instance : Cost Budget tab on Project Screen. This already shows total when grouped by task but i wanted it visible directly, without being grouped. Also it loses cost projection data when grouped by task…
Pretty sure the concept will work on any screen/tab. 

There is a CalculateSumTotal function/method within PX.Objects.Common.Extensions which can be used to get the totals for all the columns in any DAC. I added the existing back end code to my extended graph, created a new list of the line data returned in the same view and did sum/total using CalculateSumTotal. 
 

 public IEnumerable costBudget()
        {
            var selectCostBudget = new PXSelect<PMCostBudget, Where<PMCostBudget.projectID, Equal<Current<PMProject.contractID>>, And<PMCostBudget.type, Equal<GL.AccountType.expense>,
              And<Where<Current<CostBudgetFilter.projectTaskID>, IsNull, Or<Current<CostBudgetFilter.projectTaskID>, Equal<PMCostBudget.projectTaskID>>>>>>,
              OrderBy<Asc<PMCostBudget.projectID, Asc<PMCostBudget.projectTaskID, Asc<PMCostBudget.inventoryID, Asc<PMCostBudget.costCodeID, Asc<PMCostBudget.accountGroupID>>>>>>>(Base);

            PXDelegateResult delResult = new PXDelegateResult();
            delResult.Capacity = 202;
            delResult.IsResultFiltered = false;
            delResult.IsResultSorted = true;
            delResult.IsResultTruncated = false;

            if (IsCostGroupByTask() && !IsCopyPaste)
            {
                var list = new List<PMCostBudget>(selectCostBudget.Select().RowCast<PMCostBudget>());

                delResult.AddRange(AggregateBudget<PMCostBudget>(list));
            }
            else
            {
                var view = new PXView(Base, false, selectCostBudget.View.BqlSelect);
                var startRow = PXView.StartRow;
                int totalRows = 0;

                var resultset = view.Select(PXView.Currents, PXView.Parameters, PXView.Searches, PXView.SortColumns, PXView.Descendings, PXView.Filters, ref startRow, PXView.MaximumRows, ref totalRows);
                PXView.StartRow = 0;
                delResult.AddRange(resultset.RowCast<PMCostBudget>());

               // Addition/modification - create a new list for the DAC and set primary keys as null                   MOD BEGIN

                List<PMCostBudget> result = new List<PMCostBudget>(selectCostBudget.Select().RowCast<PMCostBudget>());

                PMCostBudget total = result.CalculateSumTotal(selectCostBudget.Cache);
                total.ProjectID = Project.Current.ContractID;
                total.ProjectTaskID = null;
                total.AccountGroupID = null;
                total.CostCodeID = null;
                total.InventoryID = null;
                total.Description = "TOTAL";
                total.UOM = null;
                total.Qty = null;
                total.CuryUnitRate = null;
                total.CuryUnitPrice = null;

                delResult.Add(total);
//Add total as new row          MOD END

            }

            return delResult;
        }