Copy combobox's attribute values from attributes screen to custom field in sales order header

Question

Hi I am trying to copy a defined attribute's combo box values from the Attributes screen (CS205000) to a custom field in the sales order header. This is my code but I don't get the combo box values populated in the field, it remains a normal text field. Could I please get some clarification on this or is it easier to directly using BQL in the DAC of the sales order custom field to achieve my requirement?

namespace PX.Objects.SO
{
  public class SOOrderEntry_Extension : PXGraphExtension<PX.Objects.SO.SOOrderEntry>
  {
    protected void SOOrder_UsrTypeOfOrder_FieldSelecting(PXCache cache, PXFieldSelectingEventArgs e)
    {
      
      List<string> allowedValues = new List<string>();
      List<string> allowedLabels = new List<string>();
      SOOrderEntry graph = (SOOrderEntry)sender.Graph;
      var query = PXSelect<
        CSAttributeDetail,
        Where<
          CSAttributeDetail.attributeID,
          Equal<Required<CSAttributeDetail.attributeID>>
        >
      >.Select(graph, "TOO");

      foreach (CSAttributeDetail attrDetail in query)
      {
        allowedValues.Add(attrDetail.ValueID);
        allowedLabels.Add(attrDetail.Description);
      }

      e.ReturnState = PXStringState.CreateInstance(
        e.ReturnState,
        50,
        true,
        typeof(SOOrderExt.usrTypeOfOrder).Name,
        false,
        -1,
        string.Empty,
        allowedValues.ToArray(),
        allowedLabels.ToArray(),
        false,
        null
      );
    }
  }
}

Attribute Screenshot

Answer 1

Hi I figured out the solution the return character length must be set to 225 and no stringlist attribute is required in the field declaration.

  protected void SOOrder_UsrTypeOfOrder_FieldSelecting(PXCache cache, PXFieldSelectingEventArgs e)
    {
      
       List<string> allowedValues = new List<string>();
       List<string> allowedLabels = new List<string>();

       
            foreach (CSAttributeDetail attrDetail in PXSelect<CSAttributeDetail,
                                                         Where<CSAttributeDetail.attributeID, Equal<Required<CSAttributeDetail.attributeID>>>>
                .Select(Base, "TOO"))
            {
                allowedValues.Add(attrDetail.ValueID);
                allowedLabels.Add(attrDetail.Description);
            }

            e.ReturnState = PXStringState.CreateInstance(e.ReturnState, 225, true, typeof(SOOrderExt.usrTypeOfOrder).Name, false, -1, string.Empty, allowedValues.ToArray(), allowedLabels.ToArray(), false, null);
      
    }