DynamicDropDown_Attribute.cs

	public class SOARDocTypesListAttribute : PXStringListAttribute, IPXRowSelectedSubscriber
	{
		public Type _Module;
		public class OrderTypesDefinition : IPrefetchable
		{
			public Dictionary<String, String> list = new Dictionary<String, String>();

			public void Prefetch()
			{
				list.Clear();
				
				foreach (PXDataRecord rec in PXDatabase.SelectMulti<SOOrderType>(
                    			new PXDataField<SOOrderType.orderType>(), 
                    			new PXDataField<SOOrderType.descr>()))
				{					
					list[rec.GetString(0)] = rec.GetString(1);
				}
			}
		}

		public SOARDocTypesListAttribute(Type module)
			: base()
		{
			_Module = module;
		}

		public void RowSelected(PXCache sender, PXRowSelectedEventArgs e)
		{
			Object row = e.Row as Object;
			String module = (String)sender.GetValue(row, _Module.Name);

			if (row != null && module != null)
			{
				if (module == arModule.value)
				{
					PXStringListAttribute.SetList(sender, row, _FieldName, new ARDocType.ListAttribute());
				}
				if (module == soModule.value)
				{
					OrderTypesDefinition def = PXDatabase.GetSlot<OrderTypesDefinition>(typeof(OrderTypesDefinition).Name, typeof(SOOrderType));
					PXStringListAttribute.SetList(sender, row, _FieldName, def.list.Keys.ToArray(), def.list.Values.ToArray());
				}
			}
		}
	}
	#endregion

DynamicDropDown_DAC.cs

[Serializable]
public class DAC : IBqlTable
{
	#region DocType
	[PXDBString(3, IsKey = true, IsFixed = false)]
	[PXUIField(DisplayName = "Doc Type", Enabled = false)]
	[SOARDocTypesListAttribute(typeof(DAC.module))]
	public string DocType { get; set; }
	public class docType : IBqlField { }
	#endregion
}