xpo-devexpress-dot-xpo-dot-persistentbase.md
Invoked when the current object is about to be initialized after its creation.
Namespace : DevExpress.Xpo
Assembly : DevExpress.Xpo.v25.2.dll
NuGet Package : DevExpress.Xpo
public virtual void AfterConstruction()
Public Overridable Sub AfterConstruction
Override this method in your PersistentBase descendants to add custom initialization logic to your persistent objects (see the code example below).
using DevExpress.Xpo;
...
public class MyDataObject : XPObject {
public MyDataObject()
: base() {
// This constructor is used when an object is loaded from a persistent storage.
// Do not place any code here.
}
public MyDataObject(Session session)
: base(session) {
// This constructor is used when an object is loaded from a persistent storage.
// Do not place any code here.
}
public override void AfterConstruction() {
base.AfterConstruction();
// Place your initialization code here.
}
}
The base AfterConstruction method implementation includes only functionality relevant for persistent objects associated with UnitOfWork. In essence, the default implementation marks the current object to be saved to a data store if both of the following conditions are met:
The example below demonstrated how to automatically populate the CreatedBy, CreatedOn, UpdatedBy, and UpdatedOn properties (audit columns) in an XAF business class.
using DevExpress.Xpo;
...
namespace YourSolutionName.BusinessObjects {
[DefaultClassOptions]
public class Contact : BaseObject {
public Contact(Session session)
: base(session) {
}
// Get a current active user
ApplicationUser GetCurrentUser() {
return Session.GetObjectByKey<ApplicationUser>(
Session.ServiceProvider.GetRequiredService<ISecurityStrategyBase>().UserId);
}
// Automatically fill the CreatedOn and CreatedBy columns
// when a current user creates a new Contact item.
public override void AfterConstruction() {
base.AfterConstruction();
CreatedOn = DateTime.Now;
CreatedBy = GetCurrentUser();
}
// Automatically fill the UpdatedOn and UpdatedBy columns
// when a current user saves a modified Contact item.
protected override void OnSaving() {
base.OnSaving();
UpdatedOn = DateTime.Now;
UpdatedBy = GetCurrentUser();
}
protected override void OnChanged(string propertyName, object oldValue, object newValue) {
base.OnChanged(propertyName, oldValue, newValue);
if(!IsLoading) {
switch(propertyName) {
// Run custom code when the "Email" property value is changed.
case nameof(Email):
UpdateContacts();
break;
}
}
}
ApplicationUser createdBy;
public ApplicationUser CreatedBy {
get { return createdBy; }
set { SetPropertyValue("CreatedBy", ref createdBy, value); }
}
DateTime createdOn;
public DateTime CreatedOn {
get { return createdOn; }
set { SetPropertyValue("CreatedOn", ref createdOn, value); }
}
ApplicationUser updatedBy;
public ApplicationUser UpdatedBy {
get { return updatedBy; }
set { SetPropertyValue("UpdatedBy", ref updatedBy, value); }
}
DateTime updatedOn;
public DateTime UpdatedOn {
get { return updatedOn; }
set { SetPropertyValue("UpdatedOn", ref updatedOn, value); }
}
}
}
The following code snippets (auto-collected from DevExpress Examples) contain references to the AfterConstruction() method.
Note
The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.
public override void AfterConstruction() {
base.AfterConstruction();
// Place here your initialization code.
public override void AfterConstruction() {
base.AfterConstruction();
// Place here your initialization code.
XPO_how-to-clone-a-persistent-object-e804/CS/SimpleObject/ObjectClass.cs#L8
public override void AfterConstruction() {
base.AfterConstruction();
}
xpo-json-serialization/CS/XpoSerialization/DxSampleModelCode/Customer.cs#L14
public Customer(Session session) : base(session) { }
public override void AfterConstruction() { base.AfterConstruction(); }
}
winforms-reporting-create-report-bound-to-xpobjectsource/CS/ORMDataModel1Code/Categories.cs#L12
public Categories(Session session) : base(session) { }
public override void AfterConstruction() { base.AfterConstruction(); }
}
XPO_how-to-clone-a-persistent-object-e804/VB/SimpleObject/ObjectClass.vb#L12
Public Overrides Sub AfterConstruction()
MyBase.AfterConstruction()
End Sub
Public Overrides Sub AfterConstruction()
MyBase.AfterConstruction()
End Sub
winforms-reporting-create-report-bound-to-xpobjectsource/VB/ORMDataModel1Code/Categories.vb#L15
Public Overrides Sub AfterConstruction()
MyBase.AfterConstruction()
End Sub
winforms-filtercontrol-implement-ifilteredcomponent/VB/Q200298/Northwind.vb#L64
Public Overrides Sub AfterConstruction()
MyBase.AfterConstruction()
End Sub
Public Overrides Sub AfterConstruction()
MyBase.AfterConstruction()
End Sub
See Also