Session.FindObject(PersistentCriteriaEvaluationBehavior, Type, CriteriaOperator) Method

Searches for the first object which matches the specified criteria.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v21.1.dll

NuGet Package: DevExpress.Xpo

Declaration

C#

public object FindObject(
    PersistentCriteriaEvaluationBehavior criteriaEvaluationBehavior,
    Type objType,
    CriteriaOperator criteria
)

VB.NET

Public Function FindObject(
    criteriaEvaluationBehavior As PersistentCriteriaEvaluationBehavior,
    objType As Type,
    criteria As CriteriaOperator
) As Object

Parameters

Name	Type	Description
criteriaEvaluationBehavior	PersistentCriteriaEvaluationBehavior	A PersistentCriteriaEvaluationBehavior enumeration value that specifies how the persistent criteria is evaluated.
objType	Type	A Type object which represents the type of objects to search for.
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;
// ...
Person personToUpdate = (Person)session.FindObject(PersistentCriteriaEvaluationBehavior.BeforeTransaction, 
    typeof(Person), 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
' ...
Dim personToUpdate As Person = CType(session.FindObject(PersistentCriteriaEvaluationBehavior.BeforeTransaction, _
    GetType(Person), 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.