Session.FindObject(PersistentCriteriaEvaluationBehavior, XPClassInfo, CriteriaOperator, Boolean) Method

Searches for the first object which matches the specified criteria.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v24.1.dll

NuGet Packages: DevExpress.Win.PivotGrid, DevExpress.Win.TreeMap, DevExpress.Xpo

NuGet Package: DevExpress.Xpo

Declaration

C#

public object FindObject(
    PersistentCriteriaEvaluationBehavior criteriaEvaluationBehavior,
    XPClassInfo classInfo,
    CriteriaOperator criteria,
    bool selectDeleted
)

VB.NET

Public Function FindObject(
    criteriaEvaluationBehavior As PersistentCriteriaEvaluationBehavior,
    classInfo As XPClassInfo,
    criteria As CriteriaOperator,
    selectDeleted As Boolean
) As Object

Parameters

Name	Type	Description
criteriaEvaluationBehavior	PersistentCriteriaEvaluationBehavior	A PersistentCriteriaEvaluationBehavior enumeration value that specifies how the persistent criteria is evaluated.
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.
selectDeleted	Boolean	true to include persistent objects marked as deleted into the search; otherwise, false.

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(PersistentCriteriaEvaluationBehavior.BeforeTransaction, 
    personClassInfo, CriteriaOperator.Parse("Name='Michael Suyama'"), true);
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(PersistentCriteriaEvaluationBehavior.BeforeTransaction, _
    personClassInfo, CriteriaOperator.Parse("Name='Michael Suyama'"), True), 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 can be optionally included in the search using the selectDeleted parameter.