XPDelayedProperty.IsLoaded Property

Gets whether the property’s value remains unassigned after the persistent object has been loaded from the data store.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v24.1.dll

NuGet Packages: DevExpress.Win.PivotGrid, DevExpress.Win.TreeMap, DevExpress.Xpo

NuGet Package: DevExpress.Xpo

Declaration

C#

public bool IsLoaded { get; }

VB.NET

Public ReadOnly Property IsLoaded As Boolean

Property Value

Type	Description
Boolean	true if the property’s value is unassigned after the persistent object has been loaded from the data store; otherwise, false.

Remarks

By default, the IsLoaded property is set to false. This means that the property’s value remains unassigned after the persistent object has been loaded from the data store. The property will be loaded the first time it is accessed.

Example

The following example demonstrates how to delay the loading of the DelayedAttachment property and improve property value update performance, by enabling the DelayedAttribute.UpdateModifiedOnly property.

Note

This solution uses the XPDelayedProperty object explicitly and doesn’t raise property change notifications in all scenarios. You may need to explicitly call the Session.Save method after modifying the property value to save changes. Alternatively, implement the delayed property as shown in the Delayed Loading article.

C#

using DevExpress.Xpo;

public class Customer : XPObject {
   // ...
   private XPDelayedProperty document = new XPDelayedProperty();
   // Improve update performance for the property's value
   // by passing true as the attribute's
   // updateModifiedOnly parameter.
   [Delayed(nameof(document), true)]
   public Byte[] DelayedAttachment {
      get { return (Byte[])document.Value; }
      set { document.Value = value; }
   }
}

VB.NET

Imports DevExpress.Xpo

Public Class Customer
   Inherits XPObject
   ' ...
   Private document As XPDelayedProperty = New XPDelayedProperty()
   ' Improve update performance for the property's value
   ' by passing true as the attribute's
   ' updateModifiedOnly parameter.
   <Delayed(NameOf(document), True)> _
   Public Property DelayedAttachment() As [Byte]()
       Get
           Return document.Value
       End Get
       Set
           document.Value = value
       End Set
   End Property
End Class