How to: Specify a Display Member (for a Lookup Editor, Detail Form Caption, etc.)

• Mar 12, 2021
• 2 minutes to read

Each business object used in an XAF application should have a default property. The default property value is treated as a human-readable identifier in an XAF application UI (e.g., FullName of a Contact, Subject of a Task, etc.). Default property values are displayed in the following:

• Detail View captions;
• the leftmost columns of List Views;
• Lookup List Views;
• Lookup Editors in an unexpanded state.

Default Property of a Business Class

It is strongly recommended that you apply the XafDefaultPropertyAttribute attribute and pass the default property name to this attribute. If you omit the XafDefaultProperty attribute, a GUID or Integer identifier may be displayed in the UI (this situation confuses end-users).

C#

using DevExpress.ExpressApp.DC;
// ...
[XafDefaultProperty("Subject")]
public class Task {
    // ...
    public string Subject { get; set; }
    // ...
}

VB.NET

<XafDefaultProperty("Subject")>
Imports DevExpress.ExpressApp.DC
' ...
Public Class Department
    ' ...
    Public Property Subject() As String
    ' ...
End Class

Alternatively, you can use the DefaultProperty attribute from the System.ComponentModel namespace.

Tip

XAF can detect the default property automatically. If a property name is Name, or it includes the Name substring, then this property is considered default, and there is no need to specify the default property explicitly.

Property Displayed in a Lookup Editor

The default property of a referenced business object is displayed in a Lookup Property Editor. If you need to use another property in lookups, use the IModelCommonMemberViewItem.LookupProperty property in the Model Editor.