expressappframework-devexpress-dot-expressapp-dot-iobjectspace-b8e8950b.md
Updates the persistent objects belonging to the current Object Space.
Namespace : DevExpress.ExpressApp
Assembly : DevExpress.ExpressApp.v25.2.dll
NuGet Package : DevExpress.ExpressApp
bool Refresh()
Function Refresh As Boolean
| Type | Description |
|---|---|
| Boolean |
true if persistent objects were refreshed; otherwise, false.
|
Use this method to update the current Object Space‘s persistent objects.
The following code snippet adds a new Contact object to a List View and refreshes the Object Space to show the new object.
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.Actions;
using DevExpress.Persistent.Base;
using MainDemo.Module.BusinessObjects;
// ...
public class AddContactController : ObjectViewController<ListView, Contact> {
public AddContactController() {
ParametrizedAction addContactAction = new ParametrizedAction(
this, "AddContact", PredefinedCategory.Edit, typeof(string));
addContactAction.Execute += AddContactAction_Execute;
}
private void AddContactAction_Execute(object sender, ParametrizedActionExecuteEventArgs e) {
using(IObjectSpace objectSpace = Application.CreateObjectSpace(typeof(Contact))) {
Contact contact = objectSpace.CreateObject<Contact>();
contact.FirstName = e.ParameterCurrentValue as string;
objectSpace.CommitChanges();
}
View.ObjectSpace.Refresh();
}
}
When you implement the IObjectSpace interface in a class that descends from BaseObjectSpace, override the protected virtual BaseObjectSpace.Reload method. The BaseObjectSpace.Refresh method calls Reload.
BaseObjectSpace.Refresh works as follows:
If no objects in the current Object Space have changed after you retrieve them or after the last commit (see IObjectSpace.CommitChanges), BaseObjectSpace.Refresh recreates the in-memory object container. It calls the Reload method, retrieves the objects again, and returns true.
If at least one object has changed, the IObjectSpace.ConfirmationRequired event occurs. Handle this event to display a confirmation window that asks whether to save changes. Use the XafApplication.AskConfirmation method. This method returns a ConfirmationResult enumeration value that matches the end user’s choice. The next actions depend on this choice.
Yes
No
Cancel
The WinModificationsController handles the IObjectSpace.ConfirmationRequired event. This Controller only activates for Detail Views in Windows Forms applications. The handler shows a confirmation window as described above. The application does not show a confirmation window when you call the Refresh method in a List View. By default, the system sets the ConfirmationResult.No value. This value discards all changes and retrieves objects again through a new database connection.
The following events related to the Refresh method are available:
To implement a refresh operation, override the BaseObjectSpace.Reload method. In this method, recreate the Object Space’s container for in-memory objects. In XPO, use XPObjectSpace.Session. In Entity Framework Core, use EFCoreObjectSpace.DbContext.
The following code snippets (auto-collected from DevExpress Examples) contain references to the Refresh() 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.
importObjectSpace.CommitChanges();
targetListView.ObjectSpace.Refresh();
}
}
View.ObjectSpace.Refresh();
testAction.Caption = "Succeeded";
End Try
View.ObjectSpace.Refresh()
testAction.Caption = "Succeeded"
See Also