XafApplication.ObjectSpaceProvider Property

Provides access to the application’s Object Space Provider.

Namespace: DevExpress.ExpressApp

Assembly: DevExpress.ExpressApp.v21.2.dll

NuGet Package: DevExpress.ExpressApp

Declaration

C#

[Browsable(false)]
public IObjectSpaceProvider ObjectSpaceProvider { get; }

VB.NET

<Browsable(False)>
Public ReadOnly Property ObjectSpaceProvider As IObjectSpaceProvider

Property Value

Type	Description
IObjectSpaceProvider	An instance of the class that implements the IObjectSpaceProvider interface.

Remarks

XAF uses an Object Space Provider to create Object Spaces. It is a class that implements members of the IObjectSpaceProvider interface. The following Object Space Provider types are supplied with XAF.

• XPObjectSpaceProvider - Creates the XPObjectSpace Object Space, which manipulates data using the XPO ORM system. An Object Space Provider of this type is created by default in the CreateDefaultObjectSpaceProvider method of the WinApplication or WebApplication descendant (see below).
• EFObjectSpaceProvider - Creates the EFObjectSpace Object Space, which manipulates data using the Entity Framework ORM system. To learn how to create an Object Space Provider of this type, refer to the How to: Use the Entity Framework Code First in XAF topic.
• SecuredObjectSpaceProvider - Creates the XPObjectSpace Object Space, taking into consideration the security permissions of the current user.
• NonPersistentObjectSpaceProvider - Creates the NonPersistentObjectSpace Object Space that manipulates non-persistent object instances.

By default, XPObjectSpaceProvider is created because the WinForms and ASP.NET Web Forms application project templates override the CreateDefaultObjectSpaceProvider method of the corresponding XafApplication descendant in the following manner:

C#

public partial class MainDemoWinApplication : WinApplication {
//...
    protected override void CreateDefaultObjectSpaceProvider(
        CreateCustomObjectSpaceProviderEventArgs args) {
        args.ObjectSpaceProvider = new XPObjectSpaceProvider(args.ConnectionString, args.Connection);
    }
}

VB.NET

Partial Public Class MainDemoWinApplication
    Inherits WinApplication
    '...
    Protected Overrides Sub CreateDefaultObjectSpaceProvider( _
    ByVal args As CreateCustomObjectSpaceProviderEventArgs)
        args.ObjectSpaceProvider = _
        New XPObjectSpaceProvider(args.ConnectionString, args.Connection)
    End Sub
End Class

The CreateDefaultObjectSpaceProvider method is called when creating an Object Space Provider during the application’s setup if a particular Object Space Provider is not passed as a parameter in the Setup method call. So, check that an Object Space Provider is not passed in your Setup method call, as in the following code.

C#

static class Program {
    // ...
    public static void Main() {
        // ...
        MainDemoWinApplication application = new MainDemoWinApplication();
        // ...
        application.Setup();
        application.Start();
        // ...
    }
}

VB.NET

Friend Class Program
    ' ...
    Public Shared Sub Main()
        ' ...
        Dim _application As MainDemoWinApplication = 
        New MainDemoWinApplication()
        ' ...
        _application.Setup()
        _application.Start()
       ' ...
    End Sub
End Class

To create an Object Space Provider, the application uses the connection string specified using the XafApplication.ConnectionString property. If you need to specify a custom connection string or create an Object Space Provider of another type, implement a custom override of the CreateDefaultObjectSpaceProvider method. Alternatively, you can handle the XafApplication.CreateCustomObjectSpaceProvider event to pass a custom Object Space Provider.

Note

XAF uses the first registered Object Space Provider for the following purposes:

• to get XafApplication.ObjectSpaceProvider and XafApplication.ConnectionString property values;
• to pass this Provider as the CustomCheckCompatibilityEventArgs‘s ObjectSpaceProvider argument;
• to update an application.

Ensure that NonPersistentObjectSpaceProvider is not the first registered Provider in your application.