NullOperator Class

Represents an operator which compares a persistent object’s property value with a null reference (Nothing in Visual Basic).

Namespace: DevExpress.Data.Filtering

Assembly: DevExpress.Data.v20.2.dll

NuGet Packages: DevExpress.Data, DevExpress.WindowsDesktop.Data

Declaration

C#

public sealed class NullOperator :
    UnaryOperator

VB.NET

Public NotInheritable Class NullOperator
    Inherits UnaryOperator

Remarks

This example represents the logical expression (DefaultAddress.City <> "Chicago" AND not (Company is null)).

C#

XPCollection collection = new XPCollection(typeof(Contact), 
    new GroupOperator(GroupOperatorType.And, 
        new BinaryOperator("DefaultAddress.City", "Chicago", BinaryOperatorType.NotEqual), 
        new NotOperator(new NullOperator("Company"))));

VB.NET

Dim collection As New XPCollection(GetType(Contact), _
    New GroupOperator(GroupOperatorType.And, _
        New BinaryOperator("DefaultAddress.City", "Chicago", BinaryOperatorType.NotEqual), _
        New NotOperator(New NullOperator("Company")) _
    ) _
)

Inheritance

Object

CriteriaOperator

UnaryOperator

NullOperator