User use Sales invoice detail and drag Ref column to update some information, example container number. 

User want to display the information at Sales invoice footer, expected result as below 

Solution : 

Step 1 : in Sales Invoice à Task àDesign à Access the format 

Step 2 : Copy and paste the script in “Scripts”

using System.Linq;
private void calc_desc_GetValue(object sender, DevExpress.XtraReports.UI.GetValueEventArgs e) {
QnEBS.BO.Sales.SalesInvoices sinv = GetCurrentRow() as QnEBS.BO.Sales.SalesInvoices;
if (sinv != null && sinv.SalesInvoiceDetailsCollection.Count > 0)
                 e.Value = string.Join(", ", sinv.SalesInvoiceDetailsCollection.OrderBy(o => o.Pos).Select(o => o.Ref4));                


Step 3 : in Field List à Point to SalesInv, Address  à Right Click à Add Calculated Field

Step 4: Edit Calculated fields

Step 5 : Edit Name to calc_desc
Note : Case sensitive

Step  6 : Click on Script

Step 7 : Select calc_desc_GetValue then click OK

Step 8 : Drag this field to the footer 

Step 9 : When Preview the result as below


Please refer to attachment