How can I change header value of a field based on currently selected row in the grid

This code worked for me 

protected void AMProdItem_UsrWorkCenterID_FieldSelecting(PXCache cache, PXFieldSelectingEventArgs e)
{
    var row = (AMProdItem)e.Row;
    if (row == null) return;

    // Retrieve WcID from a matching AMProdOper record
    AMProdOper relatedOper = PXSelect<AMProdOper,
 Where<AMProdOper.orderType, Equal<Required<AMProdOper.orderType>>,
 And<AMProdOper.prodOrdID, Equal<Required<AMProdOper.prodOrdID>>>>
>.Select(Base, row.OrderType, row.ProdOrdID);

    if (relatedOper != null)
    {
        // Display WcID in UsrWorkCenterID field
        e.ReturnValue = relatedOper.WcID;

        // Optionally, disable editing for display-only field
        if (e.Row != null && e.IsAltered)
        {
            e.ReturnState = PXFieldState.CreateInstance(e.ReturnValue, typeof(string), false, false, null, null, null, null, nameof(AMProdItemExt.usrWorkCenterID), null, null, null, PXErrorLevel.Undefined, false, true, null, PXUIVisibility.Visible, null, null, null);
        }
    }
}

 protected void AMProdOper_RowSelected(PXCache sender, PXRowSelectedEventArgs e)
        {
            var oper = (AMProdOper)e.Row;
            if (oper != null)
            {
                var currentProdItem = Base.ProdItemRecords.Current;
                //  updating UsrDisplayWcID until after the current event.
                sender.Graph.RowSelected.AddHandler<AMProdItem>((cache, args) => DeferUpdateUsrDisplayWcID(cache, oper.WcID));
            }
        }

        // Update UsrDisplayWcID after the RowSelected event completes.
        private void DeferUpdateUsrDisplayWcID(PXCache cache, string wcID)
        {
            var currentProdItem = Base.ProdItemRecords.Current;
            if (currentProdItem != null)
            {
                var prodItemExt = cache.GetExtension<AMProdItemExt>(currentProdItem);
                if (prodItemExt.UsrDisplayWcID != wcID)
                {
                    try
                    {
                        // Set and update the UsrDisplayWcID field.
                        cache.SetValueExt<AMProdItemExt.usrDisplayWcID>(currentProdItem, wcID);
                        cache.Update(currentProdItem);
                        // Save changes to persist in the database.
                        Base.Actions.PressSave();
                    }
                    catch (Exception ex)
                    {
                        // Log error and rethrow.
                        PXTrace.WriteError(ex);
                    }
                }
            }
        }
    }
}

There were some issues with the code above. This code works fine. If any changes, I'll update them here

Hi

This code functions well, but there's a minor issue: the UsrWorkCenterID field doesn't update automatically. I need to clear the current record to obtain the new value. I'm not sure if this requires changes to the layout properties. If anyone knows how to resolve this, please share the solution.

Thank you.

protected void AMProdItem_UsrWorkCenterID_FieldSelecting(PXCache cache, PXFieldSelectingEventArgs e)
        {
            // Getting the production item data.
            var prodItemRow = (AMProdItem)e.Row;
            if (prodItemRow == null) return; // If there's no data, return.

            // Trying to find the current operation info.
            var currentOperRow = Base.Caches<AMProdOper>().Current as AMProdOper;

            // If the current operation matches the item's details, use its Work Center ID.
            if (currentOperRow != null && currentOperRow.ProdOrdID == prodItemRow.ProdOrdID)
            {
                e.ReturnValue = currentOperRow.WcID;
            }
            else
            {
                // If not, look for related operations to find a Work Center ID.
                var relatedOper = PXSelect<AMProdOper,
                    Where<AMProdOper.orderType, Equal<Required<AMProdOper.orderType>>,
                    And<AMProdOper.prodOrdID, Equal<Required<AMProdOper.prodOrdID>>>>
                >.SelectWindowed(Base, 0, 1, prodItemRow.OrderType, prodItemRow.ProdOrdID);

                // If a related operation is found, set the return value to its Work Center ID.
                if (relatedOper != null && relatedOper.Count > 0)
                {
                    e.ReturnValue = ((AMProdOper)relatedOper).WcID;
                }
            }
        }

Take a note of aspx page changes with RepaintControlIDs as show on the screenshot:

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https://help.acumatica.com/(W(1))/Wiki/ShowWiki.aspx?pageid=a23d3b80-e763-46da-9beb-c1447ceae4b3

and also developers guide: https://www.acumatica.com/media/2020/02/AcumaticaFramework_DevelopmentGuide.pdf

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