XPQuery<T>.TransformExpression(Session, Expression<Func<T, Boolean>>) Method

Converts a lambda expression into an instance of the CriteriaOperator class descendant.

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 static CriteriaOperator TransformExpression(
    Session session,
    Expression<Func<T, bool>> expression
)

VB.NET

Public Shared Function TransformExpression(
    session As Session,
    expression As Expression(Of Func(Of T, Boolean))
) As CriteriaOperator

Parameters

Name	Type	Description
session	Session	A Session class instance whose Session.Dictionary and Session.TypesManager are used in the construction of the criteria operator.
expression	Expression<Func<T, Boolean>>	A lambda expression.

Returns

Type	Description
CriteriaOperator	An instance of the CriteriaOperator class descendant that represents the lambda expression.

Example

In the following code snippet the customers collection will contain only the customers named “Bob”:

C#

using DevExpress.Xpo;
using DevExpress.Data.Filtering;

//...

Session MainSession = new Session();
XPQuery<Customer> customersQuery = new XPQuery<Customer>(MainSession);

CriteriaOperator criteria = customersQuery.TransformExpression(c => c.Name == "Bob");

XPCollection<Customer> customers = new XPCollection<Customer>(MainSession);
customers.Criteria = criteria;

VB.NET

Imports DevExpress.Xpo
Imports DevExpress.Data.Filtering

'...

Dim MainSession As New Session()
Dim customersQuery As XPQuery(Of Customer) = New XPQuery(Of Customer)(MainSession)

Dim criteria As CriteriaOperator = customersQuery.TransformExpression(Function(c) c.Name = "Bob")

Dim customers As XPCollection(Of Customer) = New XPCollection(Of Customer)(MainSession)
customers.Criteria = criteria