Session.FindObject(XPClassInfo, CriteriaOperator) Method

Searches for the first object which matches the specified criteria.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v24.2.dll

Declaration

C#

public object FindObject(
    XPClassInfo classInfo,
    CriteriaOperator criteria
)

VB.NET

Public Function FindObject(
    classInfo As XPClassInfo,
    criteria As CriteriaOperator
) As Object

Parameters

Name	Type	Description
classInfo	XPClassInfo	An XPClassInfo object which contains the metadata information of the class.
criteria	CriteriaOperator	A CriteriaOperator descendant which represents the criteria to match persistent objects.

Returns

Type	Description
Object	An object which represents the first persistent object which matches the specified criteria. null (Nothing in Visual Basic) if no persistent object which matches the criteria is found.

Remarks

The example below demonstrates how to use this method. Here, session is the Session instance.

C#

using DevExpress.Data.Filtering;
using DevExpress.Xpo;
using DevExpress.Xpo.Metadata;
// ...
XPClassInfo personClassInfo = session.GetClassInfo(typeof(Person));
Person personToUpdate = (Person)session.FindObject(personClassInfo, 
    CriteriaOperator.Parse("Name='Michael Suyama'"));
if(personToUpdate != null) {
    personToUpdate.Birthday = new DateTime(1986, 10, 31);
    session.Save(personToUpdate);
}

VB.NET

Imports DevExpress.Data.Filtering
Imports DevExpress.Xpo
Imports DevExpress.Xpo.Metadata
' ...
Dim personClassInfo As XPClassInfo = session.GetClassInfo(GetType(Person))
Dim personToUpdate As Person = CType(session.FindObject(personClassInfo, _
    CriteriaOperator.Parse("Name='Michael Suyama'")), Person)
If personToUpdate IsNot Nothing Then
    personToUpdate.Birthday = New Date(1986, 10, 31)
    session.Save(personToUpdate)
End If

Persistent objects that are marked as deleted in the database (see Deferred and Immediate Object Deletion) are not included in the search.

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the FindObject(XPClassInfo, CriteriaOperator) 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.

C#

XPO_how-to-persist-metadata-e269/CS/Program.cs#L110

XPClassInfo classCustomer = dataSession.GetClassInfo("", "Customer");
XPBaseObject customer = (XPBaseObject)dataSession.FindObject(classCustomer, null);
IList orders = (IList)customer.GetMemberValue("Orders");

VB.NET

XPO_how-to-persist-metadata-e269/VB/Program.vb#L114

Dim classCustomer As XPClassInfo = dataSession.GetClassInfo("", "Customer")
Dim customer As XPBaseObject = CType(dataSession.FindObject(classCustomer, Nothing), XPBaseObject)
Dim orders As IList = DirectCast(customer.GetMemberValue("Orders"), IList)