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.NET Standard 2.0+

PersistentBase.OnSaving() Method

Invoked when the current object is about to be saved.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v22.1.dll


protected virtual void OnSaving()


Override this method in your PersistentBase descendants to add custom logic to a persistent object when the object is about to be saved.


The example below demonstrated how to automatically populate the CreatedBy, CreatedOn, UpdatedBy, and UpdatedOn properties (audit columns) in a business class.

using DevExpress.Xpo;  

namespace YourSolutionName.BusinessObjects {  
    public class Contact : BaseObject {  
        public Contact(Session session)  
            : base(session) {  
        // Get a current active user
        User GetCurrentUser() {  
            return Session.GetObjectByKey<User>(SecuritySystem.CurrentUserId);  
        // Automatically fill the CreatedOn and CreatedBy columns 
        // when a current user creates a new Contact item.
        public override void 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() {  
            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):

        User createdBy;  
        public User CreatedBy {  
            get { return createdBy; }  
            set { SetPropertyValue("CreatedBy", ref createdBy, value); }  
        DateTime createdOn;  
        public DateTime CreatedOn {  
            get { return createdOn; }  
            set { SetPropertyValue("CreatedOn", ref createdOn, value); }  
        User updatedBy;  
        public User 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 snippet (auto-collected from DevExpress Examples) contains a reference to the OnSaving() method.


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See Also