Acumatica开发入门：如何为采购订单自定义字段设置默认值

Hey there! Since you already have Odoo/NetSuite experience and know how to create custom fields in Acumatica via Customization Projects + Layout Editor, let's dive straight into the logic to auto-populate that PO line field from the item's attributes.

First, confirm the exact field on the InventoryItem DAC (Acumatica's data access class for items) that holds the attribute you want to pull. This could be:

• A system-provided attribute (like ItemClassID related values, Descr, etc.)
• A custom attribute you created (e.g., UsrShelfLocation, UsrPreferredVendorCode)

Acumatica uses server-side C# event handlers to handle this kind of dynamic value assignment—think of this as similar to Odoo's onchange methods or NetSuite's fieldChanged scripts. We'll use two key events for PO lines:

1. FieldUpdated (triggers when the user selects an item on the PO line)
2. RowInserted (triggers when a new PO line is added, e.g., from a template or copy)

Here's a complete code example you can adapt to your custom fields:

using PX.Data;

public class POLineExtension : PXCacheExtension<POLine>
{
    // Define your custom PO line field (match the one you created in Layout Editor)
    #region UsrPOCustomAttribute
    [PXDBString(100)]
    [PXUIField(DisplayName = "Item Attribute Value")]
    public virtual string UsrPOCustomAttribute { get; set; }
    public abstract class usrPOCustomAttribute : PX.Data.BQL.BqlString.Field<usrPOCustomAttribute> { }
    #endregion

    // Trigger when the user selects/changes the InventoryID on the PO line
    protected void _(Events.FieldUpdated<POLine.inventoryID> e)
    {
        POLine poLine = e.Row;
        if (poLine == null) return;

        // Fetch the corresponding InventoryItem record
        InventoryItem item = PXSelect<InventoryItem, 
            Where<InventoryItem.inventoryID, Equal<Required<POLine.inventoryID>>>>
            .Select(Base, poLine.InventoryID);
        
        if (item != null)
        {
            // Assign the item's attribute to your PO line custom field
            // Replace "item.UsrYourItemAttribute" with your actual item field
            poLine.GetExtension<POLineExtension>().UsrPOCustomAttribute = item.UsrYourItemAttribute;
        }
    }

    // Trigger when a new PO line is inserted (covers cases like copying lines)
    protected void _(Events.RowInserted<POLine> e)
    {
        POLine poLine = e.Row;
        if (poLine?.InventoryID == null) return;

        // Reuse the same logic as FieldUpdated to populate the field
        InventoryItem item = PXSelect<InventoryItem, 
            Where<InventoryItem.inventoryID, Equal<Required<POLine.inventoryID>>>>
            .Select(Base, poLine.InventoryID);
        
        if (item != null)
        {
            poLine.GetExtension<POLineExtension>().UsrPOCustomAttribute = item.UsrYourItemAttribute;
        }
    }
}

1. Add this code to your Customization Project (under Code Files > New)
2. Compile the project to catch any syntax errors
3. Publish the customization to your Acumatica instance
4. Test by creating a new Purchase Order: add a line, select an item, and verify your custom field auto-populates with the item's attribute value.

• This works like an Odoo onchange method (runs server-side when a field changes)
• Similar to NetSuite's beforeLoad or fieldChanged scripts, but Acumatica uses compiled C# for better performance and data consistency.

内容的提问来源于stack exchange，提问作者user8403508