FilterControl.MaxOperandsCount Property

Gets or sets the maximum number of atomic operands simultaneously displayed within a group operand. If there are more atomic operands in display mode, the group operand’s text representation will be trimmed. In edit mode, the group operand’s values will be edited via a CheckedComboBoxEdit control. This feature is supported when the FilterControl is bound to XtraGrid.

Namespace: DevExpress.XtraEditors

Assembly: DevExpress.XtraEditors.v24.2.dll

Declaration

C#

[DefaultValue(20)]
[DXCategory("Behavior")]
public int MaxOperandsCount { get; set; }

VB.NET

<DXCategory("Behavior")>
<DefaultValue(20)>
Public Property MaxOperandsCount As Integer

Property Value

Type	Default	Description
Int32	20	An integer value that specifies the maximum number of atomic operands simultaneously displayed within a group operand.

Remarks

Group operands are used to define values for the Is any of and Is none of operators:

If the number of atomic operands in a group operand is equal to or less than MaxOperandsCount, the FilterControl displays all the atomic operands, separating them with a comma. Each operand can be edited within a separate edit box:

If the number of atomic operands is greater than MaxOperandsCount, the following takes place if the FilterControl is bound to Grid Control via the FilterControl.SourceControl property:

• in display mode, the group operand’s text representation is trimmed.

  

• in edit mode, the group operand is edited via a CheckedComboBoxEdit control.

  

If the FilterControl is not bound to XtraGrid, the CheckedComboBoxEdit control can still be used to present a group operand’s value. The following example shows how to accomplish this.

Example - How to use CheckedComboBox control when editing IsAnyOf and IsNoneOf operands in FilterControl bound to any object except XtraGrid

In FilterControl, there are two operand presentation modes when editing the "Is Any Of" and "Is None Of" group operands: simple and advanced. The simple mode is enabled when the number of atomic operands in a group operand is equal to or less than FilterControl.MaxOperandCount. Otherwise the advanced mode is activated, where:- in display mode, a group operand's text presentation is trimmed.- in edit mode, the group operand's values are edited with the help of the CheckedComboBoxEdit control. The advanced operand presentation mode is supported when the FilterControl is bound to the XtraGrid. Otherwise, this feature is not supported. This example shows how to overcome this limitation by creating a custom SourceControl component and an UnbounFilterColumn descendant.In the descendant class two members are overridden:- The AllowItemCollectionEditor property determines whether or not the feature is allowed for certain columns.- The CreateItemCollectionEditor method creates a CheckedComboBoxEdit control.

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace B217847Example
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}

CustomFilterColumn.cs

using System;
using System.Linq;
using System.Collections;
using System.ComponentModel;
using System.Collections.Generic;
using DevExpress.XtraEditors.Filtering;
using DevExpress.XtraEditors.Repository;
using DevExpress.Data.Filtering.Helpers;

namespace B217847Example
{
    class CustomFilterColumn : UnboundFilterColumn
    {
        public CustomFilterColumn(string columnCaption, string fieldName, Type columnType, 
            RepositoryItem columnEdit, FilterColumnClauseClass clauseClass, FilterAdapter owner)
            : base(columnCaption, fieldName, columnType, columnEdit, clauseClass) { 
            this.Owner = owner; 
        }

        protected readonly FilterAdapter Owner;

        Object DataSource {
            get { return Owner.DataSource; } 
        }

        private void GetAllUniqueValues(IList List, List<Object> op)
        {
            foreach (object Lob in List)
            {
                foreach (PropertyDescriptor pd in Owner.GetProperties())
                {
                    if (pd.Name == FieldName)
                        op.Add(pd.GetValue(Lob));

                }

            }
        }
        public override RepositoryItem CreateItemCollectionEditor()
        {
            FilterRepositoryItemCheckedComboBoxEdit re = new FilterRepositoryItemCheckedComboBoxEdit();

            if (DataSource == null)
                return re;

            IList List;

            if (DataSource is IList)
                List = DataSource as IList;
            else
            {
                IListSource Ilist = DataSource as IListSource;
                List = Ilist.GetList();
            }

            List<Object> op = new List<object>();
            GetAllUniqueValues(List, op);

            foreach (Object Value in op)
            {
                if (Value.ToString() != "" && re.Items[Value] == null)
                    re.Items.Add(Value, Value.ToString());
            }

            return re;
        }


        public override bool AllowItemCollectionEditor
        {
            get
            {
                return true;
            }
        }

    }
}

DataTableHelper.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;

namespace B217847Example
{
    public class DataTableHelper
    {
        public static void GetDataTable(DataTable table)
        {
            DataRow Row1 = table.NewRow();
            Row1["Number"] = 23;
            Row1["Name"] = "Mike";
            Row1["Date"] = new DateTime(2012, 9, 18);
            table.Rows.Add(Row1);

            DataRow Row2 = table.NewRow();
            Row2["Number"] = 12;
            Row2["Name"] = "Jon";
            Row2["Date"] = new DateTime(2012, 9, 19);
            table.Rows.Add(Row2);

            DataRow Row3 = table.NewRow();
            Row3["Number"] = 1;
            Row3["Name"] = "Bill";
            Row3["Date"] = new DateTime(2012, 9, 20);
            table.Rows.Add(Row3);

            DataRow Row4 = table.NewRow();
            Row4["Number"] = 121;
            Row4["Name"] = "Bruce";
            Row4["Date"] = new DateTime(2012, 9, 21);
            table.Rows.Add(Row4);

            DataRow Row5 = table.NewRow();
            Row5["Number"] = 132;
            Row5["Name"] = "Lex";
            Row5["Date"] = new DateTime(2012, 9, 22);
            table.Rows.Add(Row5);
        }
    }
}

FilterAdapter.cs

using System;
using System.Linq;
using System.Collections;
using System.ComponentModel;
using System.Collections.Generic;
using DevExpress.XtraEditors.Filtering;
using DevExpress.XtraEditors.Repository;
using DevExpress.Data.Filtering;
using DevExpress.Data.Filtering.Helpers;

namespace B217847Example
{
    [ToolboxItem(true)]
    public class FilterAdapter :Component, IFilteredComponent, ISupportInitialize
    {
        [AttributeProvider(typeof(IListSource))]
        public object DataSource
        {
            get { return fDataSource; }
            set
            {
                IBindingList oldBindingList = fDataSource as IBindingList;
                if (oldBindingList != null)
                    oldBindingList.ListChanged -= OnListChanged;
                fDataSource = value;
                IBindingList newBindingList = fDataSource as IBindingList;
                if (newBindingList != null)
                    newBindingList.ListChanged += OnListChanged;
            }
        }

        CriteriaOperator fRowCriteria;
        [Browsable(false), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public virtual CriteriaOperator RowCriteria
        {
            get { return fRowCriteria; }
            set {
                if (ReferenceEquals(fRowCriteria, value)) return;
                fRowCriteria = value;
                RaiseRowFilterChanged();
            }
        }

        private object fDataSource;
        static RepositoryItemTextEdit DefaultEditor = new RepositoryItemTextEdit();
        static RepositoryItemDateEdit DefaultDateEditor = new RepositoryItemDateEdit();

        protected virtual FilterColumnCollection GetFilterColumns()
        {
            PropertyDescriptorCollection PDC = GetProperties();
            List<PropertyDescriptor> td = FilterPropertyDescriptionCollection(PDC);
            return GetFilterColumnsCollection(td);

        }

        public PropertyDescriptorCollection GetProperties()
        {
            IList list = DataSource as IList;
            if (list == null)
                if (DataSource is IListSource)
                    list = ((IListSource)DataSource).GetList();

            if (list == null)
                return new PropertyDescriptorCollection(new PropertyDescriptor[0], true);

            ITypedList typedList = list as ITypedList;
            if (typedList == null)
            {
                if (list.Count > 0)
                    return TypeDescriptor.GetProperties(list[0]);
            }
            else return typedList.GetItemProperties(new PropertyDescriptor[0]);
            return new PropertyDescriptorCollection(new PropertyDescriptor[0], true);
        }

        private static List<PropertyDescriptor> FilterPropertyDescriptionCollection(PropertyDescriptorCollection PDC)
        {
            List<PropertyDescriptor> td = new List<PropertyDescriptor>();
            foreach (PropertyDescriptor pd in PDC)
            {
                object op = pd.PropertyType;
                if (!pd.PropertyType.IsClass || (pd.PropertyType == typeof(string)))
                    td.Add(pd);

            }
            return td;
        }

        private FilterColumnCollection GetFilterColumnsCollection(List<PropertyDescriptor> td)
        {
            FilterColumnCollection filterCollection = new FilterColumnCollection();
            foreach (PropertyDescriptor pd in td)
            {

                CustomFilterColumn UFC = new CustomFilterColumn(pd.DisplayName, pd.Name,
                    pd.PropertyType, GetDefaultEditor(pd.PropertyType), GetClauseClass(pd.PropertyType), this);
                filterCollection.Add(UFC);
            }
            return filterCollection;
        }

        static FilterColumnClauseClass GetClauseClass(Type type)
        {
            if (type == typeof(string))
                return FilterColumnClauseClass.String;
            if (type == typeof(DateTime))
                return FilterColumnClauseClass.DateTime;
            return FilterColumnClauseClass.Generic;
        }

        static RepositoryItem GetDefaultEditor(Type type)
        {
            if (type == typeof(DateTime))
                return DefaultDateEditor;
            return DefaultEditor;
        }

        private void OnListChanged(object sender, ListChangedEventArgs e)
        {
            if (e.ListChangedType == ListChangedType.PropertyDescriptorAdded || 
                e.ListChangedType == ListChangedType.PropertyDescriptorDeleted ||
                e.ListChangedType == ListChangedType.PropertyDescriptorChanged)
                RaisePropertiesChanged();
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                IBindingList oldBindingList = fDataSource as IBindingList;
                if (oldBindingList != null)
                    oldBindingList.ListChanged -= OnListChanged;
            }
            base.Dispose(disposing);
        }

        public event EventHandler RowFilterChanged
        {
            add { Events.AddHandler(fRowFilterChanged, value); }
            remove { Events.RemoveHandler(fRowFilterChanged, value); }
        }

        #region IFilteredComponent
        IBoundPropertyCollection IFilteredComponent.CreateFilterColumnCollection()
        {
            if (Initializing) return new FilterColumnCollection();
            return GetFilterColumns();
        }

        static readonly object fPropertiesChanged = new object();
        event EventHandler IFilteredComponentBase.PropertiesChanged
        {
            add { Events.AddHandler(fPropertiesChanged, value); }
            remove { Events.RemoveHandler(fPropertiesChanged, value); }
        }

        void RaisePropertiesChanged()
        {
            EventHandler handler = Events[fPropertiesChanged] as EventHandler;
            if (handler != null)
                handler(this, EventArgs.Empty);
        }

        CriteriaOperator IFilteredComponentBase.RowCriteria
        {
            get { return RowCriteria; }
            set { RowCriteria = value; }
        }

        static readonly object fRowFilterChanged = new object();
        event EventHandler IFilteredComponentBase.RowFilterChanged
        {
            add { RowFilterChanged += value; }
            remove { RowFilterChanged -= value; }
        }

        void RaiseRowFilterChanged()
        {
            EventHandler handler = Events[fRowFilterChanged] as EventHandler;
            if (handler != null)
                handler(this, EventArgs.Empty);
        }
        #endregion

        #region ISupportInitialize
        bool Initializing;
        void ISupportInitialize.BeginInit()
        {
            Initializing = true;
        }

        void ISupportInitialize.EndInit()
        {
            Initializing = false;
            RaisePropertiesChanged();
        }
        #endregion
    }
}

Form1.cs

using System;
using System.Linq;
using System.Windows.Forms;
using System.Collections.Generic;

namespace B217847Example
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            DataTableHelper.GetDataTable(dtTest);
        }

        private void OnFilterAdapterRowFilterChanged(object sender, EventArgs e)
        {
            gridView1.ActiveFilterCriteria = filterAdapter1.RowCriteria;
        }

        private void OnApplyFilterButtonClick(object sender, EventArgs e)
        {
            filterControl1.ApplyFilter();
        }
    }
}

Program.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Windows.Forms

Namespace B217847Example
    Friend NotInheritable Class Program
        ''' <summary>
        ''' The main entry point for the application.
        ''' </summary>
        Private Sub New()
        End Sub
        <STAThread> _
        Shared Sub Main()
            Application.EnableVisualStyles()
            Application.SetCompatibleTextRenderingDefault(False)
            Application.Run(New Form1())
        End Sub
    End Class
End Namespace

CustomFilterColumn.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Linq
Imports System.Collections
Imports System.ComponentModel
Imports System.Collections.Generic
Imports DevExpress.XtraEditors.Filtering
Imports DevExpress.XtraEditors.Repository
Imports DevExpress.Data.Filtering.Helpers

Namespace B217847Example
    Friend Class CustomFilterColumn
        Inherits UnboundFilterColumn
        Public Sub New(ByVal columnCaption As String, ByVal fieldName As String, ByVal columnType As Type, ByVal columnEdit As RepositoryItem, ByVal clauseClass As FilterColumnClauseClass, ByVal owner As FilterAdapter)
            MyBase.New(columnCaption, fieldName, columnType, columnEdit, clauseClass)
            Me.Owner = owner
        End Sub

        Protected ReadOnly Owner As FilterAdapter

        Private ReadOnly Property DataSource() As Object
            Get
                Return Owner.DataSource
            End Get
        End Property

        Private Sub GetAllUniqueValues(ByVal List As IList, ByVal op As List(Of Object))
            For Each Lob As Object In List
                For Each pd As PropertyDescriptor In Owner.GetProperties()
                    If pd.Name = FieldName Then
                        op.Add(pd.GetValue(Lob))
                    End If

                Next pd

            Next Lob
        End Sub
        Public Overrides Function CreateItemCollectionEditor() As RepositoryItem
            Dim re As New FilterRepositoryItemCheckedComboBoxEdit()

            If DataSource Is Nothing Then
                Return re
            End If

            Dim List As IList

            If TypeOf DataSource Is IList Then
                List = TryCast(DataSource, IList)
            Else
                Dim Ilist As IListSource = TryCast(DataSource, IListSource)
                List = Ilist.GetList()
            End If

            Dim op As New List(Of Object)()
            GetAllUniqueValues(List, op)

            For Each Value As Object In op
                If Value.ToString() <> "" AndAlso re.Items(Value) Is Nothing Then
                    re.Items.Add(Value, Value.ToString())
                End If
            Next Value

            Return re
        End Function


        Public Overrides ReadOnly Property AllowItemCollectionEditor() As Boolean
            Get
                Return True
            End Get
        End Property

    End Class
End Namespace

Form1.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Linq
Imports System.Windows.Forms
Imports System.Collections.Generic

Namespace B217847Example
    Partial Public Class Form1
        Inherits Form
        Public Sub New()
            InitializeComponent()
            DataTableHelper.GetDataTable(dtTest)
        End Sub

        Private Sub OnFilterAdapterRowFilterChanged(ByVal sender As Object, ByVal e As EventArgs) Handles filterAdapter1.RowFilterChanged
            gridView1.ActiveFilterCriteria = filterAdapter1.RowCriteria
        End Sub

        Private Sub OnApplyFilterButtonClick(ByVal sender As Object, ByVal e As EventArgs) Handles simpleButton1.Click
            filterControl1.ApplyFilter()
        End Sub
    End Class
End Namespace

DataTableHelper.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Text
Imports System.Data

Namespace B217847Example
    Public Class DataTableHelper
        Public Shared Sub GetDataTable(ByVal table As DataTable)
            Dim Row1 As DataRow = table.NewRow()
            Row1("Number") = 23
            Row1("Name") = "Mike"
            Row1("Date") = New DateTime(2012, 9, 18)
            table.Rows.Add(Row1)

            Dim Row2 As DataRow = table.NewRow()
            Row2("Number") = 12
            Row2("Name") = "Jon"
            Row2("Date") = New DateTime(2012, 9, 19)
            table.Rows.Add(Row2)

            Dim Row3 As DataRow = table.NewRow()
            Row3("Number") = 1
            Row3("Name") = "Bill"
            Row3("Date") = New DateTime(2012, 9, 20)
            table.Rows.Add(Row3)

            Dim Row4 As DataRow = table.NewRow()
            Row4("Number") = 121
            Row4("Name") = "Bruce"
            Row4("Date") = New DateTime(2012, 9, 21)
            table.Rows.Add(Row4)

            Dim Row5 As DataRow = table.NewRow()
            Row5("Number") = 132
            Row5("Name") = "Lex"
            Row5("Date") = New DateTime(2012, 9, 22)
            table.Rows.Add(Row5)
        End Sub
    End Class
End Namespace

FilterAdapter.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Linq
Imports System.Collections
Imports System.ComponentModel
Imports System.Collections.Generic
Imports DevExpress.XtraEditors.Filtering
Imports DevExpress.XtraEditors.Repository
Imports DevExpress.Data.Filtering
Imports DevExpress.Data.Filtering.Helpers

Namespace B217847Example
    <ToolboxItem(True)> _
    Public Class FilterAdapter
        Inherits Component
        Implements IFilteredComponent, ISupportInitialize
        <AttributeProvider(GetType(IListSource))> _
        Public Property DataSource() As Object
            Get
                Return fDataSource
            End Get
            Set(ByVal value As Object)
                Dim oldBindingList As IBindingList = TryCast(fDataSource, IBindingList)
                If oldBindingList IsNot Nothing Then
                    RemoveHandler oldBindingList.ListChanged, AddressOf OnListChanged
                End If
                fDataSource = value
                Dim newBindingList As IBindingList = TryCast(fDataSource, IBindingList)
                If newBindingList IsNot Nothing Then
                    AddHandler newBindingList.ListChanged, AddressOf OnListChanged
                End If
            End Set
        End Property

        Private fRowCriteria As CriteriaOperator
        <Browsable(False), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)> _
        Public Overridable Property RowCriteria() As CriteriaOperator
            Get
                Return fRowCriteria
            End Get
            Set(ByVal value As CriteriaOperator)
                If ReferenceEquals(fRowCriteria, value) Then
                    Return
                End If
                fRowCriteria = value
                RaiseRowFilterChanged()
            End Set
        End Property

        Private fDataSource As Object
        Private Shared DefaultEditor As New RepositoryItemTextEdit()
        Private Shared DefaultDateEditor As New RepositoryItemDateEdit()

        Protected Overridable Function GetFilterColumns() As FilterColumnCollection
            Dim PDC As PropertyDescriptorCollection = GetProperties()
            Dim td As List(Of PropertyDescriptor) = FilterPropertyDescriptionCollection(PDC)
            Return GetFilterColumnsCollection(td)

        End Function

        Public Function GetProperties() As PropertyDescriptorCollection
            Dim list As IList = TryCast(DataSource, IList)
            If list Is Nothing Then
                If TypeOf DataSource Is IListSource Then
                    list = (CType(DataSource, IListSource)).GetList()
                End If
            End If

            If list Is Nothing Then
                Return New PropertyDescriptorCollection(New PropertyDescriptor(){}, True)
            End If

            Dim typedList As ITypedList = TryCast(list, ITypedList)
            If typedList Is Nothing Then
                If list.Count > 0 Then
                    Return TypeDescriptor.GetProperties(list(0))
                End If
            Else
                Return typedList.GetItemProperties(New PropertyDescriptor(){})
            End If
            Return New PropertyDescriptorCollection(New PropertyDescriptor(){}, True)
        End Function

        Private Shared Function FilterPropertyDescriptionCollection(ByVal PDC As PropertyDescriptorCollection) As List(Of PropertyDescriptor)
            Dim td As New List(Of PropertyDescriptor)()
            For Each pd As PropertyDescriptor In PDC
                Dim op As Object = pd.PropertyType
                If (Not pd.PropertyType.IsClass) OrElse (pd.PropertyType Is GetType(String)) Then
                    td.Add(pd)
                End If

            Next pd
            Return td
        End Function

        Private Function GetFilterColumnsCollection(ByVal td As List(Of PropertyDescriptor)) As FilterColumnCollection
            Dim filterCollection As New FilterColumnCollection()
            For Each pd As PropertyDescriptor In td

                Dim UFC As New CustomFilterColumn(pd.DisplayName, pd.Name, pd.PropertyType, GetDefaultEditor(pd.PropertyType), GetClauseClass(pd.PropertyType), Me)
                filterCollection.Add(UFC)
            Next pd
            Return filterCollection
        End Function

        Private Shared Function GetClauseClass(ByVal type As Type) As FilterColumnClauseClass
            If type Is GetType(String) Then
                Return FilterColumnClauseClass.String
            End If
            If type Is GetType(DateTime) Then
                Return FilterColumnClauseClass.DateTime
            End If
            Return FilterColumnClauseClass.Generic
        End Function

        Private Shared Function GetDefaultEditor(ByVal type As Type) As RepositoryItem
            If type Is GetType(DateTime) Then
                Return DefaultDateEditor
            End If
            Return DefaultEditor
        End Function

        Private Sub OnListChanged(ByVal sender As Object, ByVal e As ListChangedEventArgs)
            If e.ListChangedType = ListChangedType.PropertyDescriptorAdded OrElse e.ListChangedType = ListChangedType.PropertyDescriptorDeleted OrElse e.ListChangedType = ListChangedType.PropertyDescriptorChanged Then
                RaisePropertiesChanged()
            End If
        End Sub

        Protected Overrides Overloads Sub Dispose(ByVal disposing As Boolean)
            If disposing Then
                Dim oldBindingList As IBindingList = TryCast(fDataSource, IBindingList)
                If oldBindingList IsNot Nothing Then
                    RemoveHandler oldBindingList.ListChanged, AddressOf OnListChanged
                End If
            End If
            MyBase.Dispose(disposing)
        End Sub

        Public Custom Event RowFilterChanged As EventHandler Implements IFilteredComponent.RowFilterChanged
            AddHandler(ByVal value As EventHandler)
                Events.AddHandler(fRowFilterChanged, value)
            End AddHandler
            RemoveHandler(ByVal value As EventHandler)
                Events.RemoveHandler(fRowFilterChanged, value)
            End RemoveHandler
            RaiseEvent(ByVal sender As System.Object, ByVal e As System.EventArgs)
            End RaiseEvent
        End Event

        #Region "IFilteredComponent"
        Private Function CreateFilterColumnCollection() As IBoundPropertyCollection Implements IFilteredComponent.CreateFilterColumnCollection
            If Initializing Then
                Return New FilterColumnCollection()
            End If
            Return GetFilterColumns()
        End Function

        Private Shared ReadOnly fPropertiesChanged As Object = New Object()
        Private Custom Event PropertiesChanged As EventHandler Implements IFilteredComponentBase.PropertiesChanged
            AddHandler(ByVal value As EventHandler)
                Events.AddHandler(fPropertiesChanged, value)
            End AddHandler
            RemoveHandler(ByVal value As EventHandler)
                Events.RemoveHandler(fPropertiesChanged, value)
            End RemoveHandler
            RaiseEvent(ByVal sender As System.Object, ByVal e As System.EventArgs)
            End RaiseEvent
        End Event

        Private Sub RaisePropertiesChanged()
            Dim handler As EventHandler = TryCast(Events(fPropertiesChanged), EventHandler)
            If handler IsNot Nothing Then
                handler(Me, EventArgs.Empty)
            End If
        End Sub

        Private Property IFilteredComponentBase_RowCriteria() As CriteriaOperator Implements IFilteredComponentBase.RowCriteria
            Get
                Return RowCriteria
            End Get
            Set(ByVal value As CriteriaOperator)
                RowCriteria = value
            End Set
        End Property

        Private Shared ReadOnly fRowFilterChanged As Object = New Object()
        Private Custom Event mRowFilterChanged As EventHandler
            AddHandler(ByVal value As EventHandler)
                AddHandler RowFilterChanged, value
            End AddHandler
            RemoveHandler(ByVal value As EventHandler)
                RemoveHandler RowFilterChanged, value
            End RemoveHandler
            RaiseEvent(ByVal sender As System.Object, ByVal e As System.EventArgs)
            End RaiseEvent
        End Event

        Private Sub RaiseRowFilterChanged()
            Dim handler As EventHandler = TryCast(Events(fRowFilterChanged), EventHandler)
            If handler IsNot Nothing Then
                handler(Me, EventArgs.Empty)
            End If
        End Sub
        #End Region

        #Region "ISupportInitialize"
        Private Initializing As Boolean
        Private Sub BeginInit() Implements ISupportInitialize.BeginInit
            Initializing = True
        End Sub

        Private Sub EndInit() Implements ISupportInitialize.EndInit
            Initializing = False
            RaisePropertiesChanged()
        End Sub
        #End Region
    End Class
End Namespace

Example

In FilterControl, there are two operand presentation modes when editing the "Is Any Of" and "Is None Of" group operands: simple and advanced. The simple mode is enabled when the number of atomic operands in a group operand is equal to or less than FilterControl.MaxOperandCount. Otherwise the advanced mode is activated, where:- in display mode, a group operand's text presentation is trimmed.- in edit mode, the group operand's values are edited with the help of the CheckedComboBoxEdit control. The advanced operand presentation mode is supported when the FilterControl is bound to the XtraGrid. Otherwise, this feature is not supported. This example shows how to overcome this limitation by creating a custom SourceControl component and an UnbounFilterColumn descendant.In the descendant class two members are overridden:- The AllowItemCollectionEditor property determines whether or not the feature is allowed for certain columns.- The CreateItemCollectionEditor method creates a CheckedComboBoxEdit control.

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace B217847Example
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}

CustomFilterColumn.cs

using System;
using System.Linq;
using System.Collections;
using System.ComponentModel;
using System.Collections.Generic;
using DevExpress.XtraEditors.Filtering;
using DevExpress.XtraEditors.Repository;
using DevExpress.Data.Filtering.Helpers;

namespace B217847Example
{
    class CustomFilterColumn : UnboundFilterColumn
    {
        public CustomFilterColumn(string columnCaption, string fieldName, Type columnType, 
            RepositoryItem columnEdit, FilterColumnClauseClass clauseClass, FilterAdapter owner)
            : base(columnCaption, fieldName, columnType, columnEdit, clauseClass) { 
            this.Owner = owner; 
        }

        protected readonly FilterAdapter Owner;

        Object DataSource {
            get { return Owner.DataSource; } 
        }

        private void GetAllUniqueValues(IList List, List<Object> op)
        {
            foreach (object Lob in List)
            {
                foreach (PropertyDescriptor pd in Owner.GetProperties())
                {
                    if (pd.Name == FieldName)
                        op.Add(pd.GetValue(Lob));

                }

            }
        }
        public override RepositoryItem CreateItemCollectionEditor()
        {
            FilterRepositoryItemCheckedComboBoxEdit re = new FilterRepositoryItemCheckedComboBoxEdit();

            if (DataSource == null)
                return re;

            IList List;

            if (DataSource is IList)
                List = DataSource as IList;
            else
            {
                IListSource Ilist = DataSource as IListSource;
                List = Ilist.GetList();
            }

            List<Object> op = new List<object>();
            GetAllUniqueValues(List, op);

            foreach (Object Value in op)
            {
                if (Value.ToString() != "" && re.Items[Value] == null)
                    re.Items.Add(Value, Value.ToString());
            }

            return re;
        }


        public override bool AllowItemCollectionEditor
        {
            get
            {
                return true;
            }
        }

    }
}

DataTableHelper.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;

namespace B217847Example
{
    public class DataTableHelper
    {
        public static void GetDataTable(DataTable table)
        {
            DataRow Row1 = table.NewRow();
            Row1["Number"] = 23;
            Row1["Name"] = "Mike";
            Row1["Date"] = new DateTime(2012, 9, 18);
            table.Rows.Add(Row1);

            DataRow Row2 = table.NewRow();
            Row2["Number"] = 12;
            Row2["Name"] = "Jon";
            Row2["Date"] = new DateTime(2012, 9, 19);
            table.Rows.Add(Row2);

            DataRow Row3 = table.NewRow();
            Row3["Number"] = 1;
            Row3["Name"] = "Bill";
            Row3["Date"] = new DateTime(2012, 9, 20);
            table.Rows.Add(Row3);

            DataRow Row4 = table.NewRow();
            Row4["Number"] = 121;
            Row4["Name"] = "Bruce";
            Row4["Date"] = new DateTime(2012, 9, 21);
            table.Rows.Add(Row4);

            DataRow Row5 = table.NewRow();
            Row5["Number"] = 132;
            Row5["Name"] = "Lex";
            Row5["Date"] = new DateTime(2012, 9, 22);
            table.Rows.Add(Row5);
        }
    }
}

FilterAdapter.cs

using System;
using System.Linq;
using System.Collections;
using System.ComponentModel;
using System.Collections.Generic;
using DevExpress.XtraEditors.Filtering;
using DevExpress.XtraEditors.Repository;
using DevExpress.Data.Filtering;
using DevExpress.Data.Filtering.Helpers;

namespace B217847Example
{
    [ToolboxItem(true)]
    public class FilterAdapter :Component, IFilteredComponent, ISupportInitialize
    {
        [AttributeProvider(typeof(IListSource))]
        public object DataSource
        {
            get { return fDataSource; }
            set
            {
                IBindingList oldBindingList = fDataSource as IBindingList;
                if (oldBindingList != null)
                    oldBindingList.ListChanged -= OnListChanged;
                fDataSource = value;
                IBindingList newBindingList = fDataSource as IBindingList;
                if (newBindingList != null)
                    newBindingList.ListChanged += OnListChanged;
            }
        }

        CriteriaOperator fRowCriteria;
        [Browsable(false), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public virtual CriteriaOperator RowCriteria
        {
            get { return fRowCriteria; }
            set {
                if (ReferenceEquals(fRowCriteria, value)) return;
                fRowCriteria = value;
                RaiseRowFilterChanged();
            }
        }

        private object fDataSource;
        static RepositoryItemTextEdit DefaultEditor = new RepositoryItemTextEdit();
        static RepositoryItemDateEdit DefaultDateEditor = new RepositoryItemDateEdit();

        protected virtual FilterColumnCollection GetFilterColumns()
        {
            PropertyDescriptorCollection PDC = GetProperties();
            List<PropertyDescriptor> td = FilterPropertyDescriptionCollection(PDC);
            return GetFilterColumnsCollection(td);

        }

        public PropertyDescriptorCollection GetProperties()
        {
            IList list = DataSource as IList;
            if (list == null)
                if (DataSource is IListSource)
                    list = ((IListSource)DataSource).GetList();

            if (list == null)
                return new PropertyDescriptorCollection(new PropertyDescriptor[0], true);

            ITypedList typedList = list as ITypedList;
            if (typedList == null)
            {
                if (list.Count > 0)
                    return TypeDescriptor.GetProperties(list[0]);
            }
            else return typedList.GetItemProperties(new PropertyDescriptor[0]);
            return new PropertyDescriptorCollection(new PropertyDescriptor[0], true);
        }

        private static List<PropertyDescriptor> FilterPropertyDescriptionCollection(PropertyDescriptorCollection PDC)
        {
            List<PropertyDescriptor> td = new List<PropertyDescriptor>();
            foreach (PropertyDescriptor pd in PDC)
            {
                object op = pd.PropertyType;
                if (!pd.PropertyType.IsClass || (pd.PropertyType == typeof(string)))
                    td.Add(pd);

            }
            return td;
        }

        private FilterColumnCollection GetFilterColumnsCollection(List<PropertyDescriptor> td)
        {
            FilterColumnCollection filterCollection = new FilterColumnCollection();
            foreach (PropertyDescriptor pd in td)
            {

                CustomFilterColumn UFC = new CustomFilterColumn(pd.DisplayName, pd.Name,
                    pd.PropertyType, GetDefaultEditor(pd.PropertyType), GetClauseClass(pd.PropertyType), this);
                filterCollection.Add(UFC);
            }
            return filterCollection;
        }

        static FilterColumnClauseClass GetClauseClass(Type type)
        {
            if (type == typeof(string))
                return FilterColumnClauseClass.String;
            if (type == typeof(DateTime))
                return FilterColumnClauseClass.DateTime;
            return FilterColumnClauseClass.Generic;
        }

        static RepositoryItem GetDefaultEditor(Type type)
        {
            if (type == typeof(DateTime))
                return DefaultDateEditor;
            return DefaultEditor;
        }

        private void OnListChanged(object sender, ListChangedEventArgs e)
        {
            if (e.ListChangedType == ListChangedType.PropertyDescriptorAdded || 
                e.ListChangedType == ListChangedType.PropertyDescriptorDeleted ||
                e.ListChangedType == ListChangedType.PropertyDescriptorChanged)
                RaisePropertiesChanged();
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                IBindingList oldBindingList = fDataSource as IBindingList;
                if (oldBindingList != null)
                    oldBindingList.ListChanged -= OnListChanged;
            }
            base.Dispose(disposing);
        }

        public event EventHandler RowFilterChanged
        {
            add { Events.AddHandler(fRowFilterChanged, value); }
            remove { Events.RemoveHandler(fRowFilterChanged, value); }
        }

        #region IFilteredComponent
        IBoundPropertyCollection IFilteredComponent.CreateFilterColumnCollection()
        {
            if (Initializing) return new FilterColumnCollection();
            return GetFilterColumns();
        }

        static readonly object fPropertiesChanged = new object();
        event EventHandler IFilteredComponentBase.PropertiesChanged
        {
            add { Events.AddHandler(fPropertiesChanged, value); }
            remove { Events.RemoveHandler(fPropertiesChanged, value); }
        }

        void RaisePropertiesChanged()
        {
            EventHandler handler = Events[fPropertiesChanged] as EventHandler;
            if (handler != null)
                handler(this, EventArgs.Empty);
        }

        CriteriaOperator IFilteredComponentBase.RowCriteria
        {
            get { return RowCriteria; }
            set { RowCriteria = value; }
        }

        static readonly object fRowFilterChanged = new object();
        event EventHandler IFilteredComponentBase.RowFilterChanged
        {
            add { RowFilterChanged += value; }
            remove { RowFilterChanged -= value; }
        }

        void RaiseRowFilterChanged()
        {
            EventHandler handler = Events[fRowFilterChanged] as EventHandler;
            if (handler != null)
                handler(this, EventArgs.Empty);
        }
        #endregion

        #region ISupportInitialize
        bool Initializing;
        void ISupportInitialize.BeginInit()
        {
            Initializing = true;
        }

        void ISupportInitialize.EndInit()
        {
            Initializing = false;
            RaisePropertiesChanged();
        }
        #endregion
    }
}

Form1.cs

using System;
using System.Linq;
using System.Windows.Forms;
using System.Collections.Generic;

namespace B217847Example
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            DataTableHelper.GetDataTable(dtTest);
        }

        private void OnFilterAdapterRowFilterChanged(object sender, EventArgs e)
        {
            gridView1.ActiveFilterCriteria = filterAdapter1.RowCriteria;
        }

        private void OnApplyFilterButtonClick(object sender, EventArgs e)
        {
            filterControl1.ApplyFilter();
        }
    }
}

Program.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Windows.Forms

Namespace B217847Example
    Friend NotInheritable Class Program
        ''' <summary>
        ''' The main entry point for the application.
        ''' </summary>
        Private Sub New()
        End Sub
        <STAThread> _
        Shared Sub Main()
            Application.EnableVisualStyles()
            Application.SetCompatibleTextRenderingDefault(False)
            Application.Run(New Form1())
        End Sub
    End Class
End Namespace

CustomFilterColumn.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Linq
Imports System.Collections
Imports System.ComponentModel
Imports System.Collections.Generic
Imports DevExpress.XtraEditors.Filtering
Imports DevExpress.XtraEditors.Repository
Imports DevExpress.Data.Filtering.Helpers

Namespace B217847Example
    Friend Class CustomFilterColumn
        Inherits UnboundFilterColumn
        Public Sub New(ByVal columnCaption As String, ByVal fieldName As String, ByVal columnType As Type, ByVal columnEdit As RepositoryItem, ByVal clauseClass As FilterColumnClauseClass, ByVal owner As FilterAdapter)
            MyBase.New(columnCaption, fieldName, columnType, columnEdit, clauseClass)
            Me.Owner = owner
        End Sub

        Protected ReadOnly Owner As FilterAdapter

        Private ReadOnly Property DataSource() As Object
            Get
                Return Owner.DataSource
            End Get
        End Property

        Private Sub GetAllUniqueValues(ByVal List As IList, ByVal op As List(Of Object))
            For Each Lob As Object In List
                For Each pd As PropertyDescriptor In Owner.GetProperties()
                    If pd.Name = FieldName Then
                        op.Add(pd.GetValue(Lob))
                    End If

                Next pd

            Next Lob
        End Sub
        Public Overrides Function CreateItemCollectionEditor() As RepositoryItem
            Dim re As New FilterRepositoryItemCheckedComboBoxEdit()

            If DataSource Is Nothing Then
                Return re
            End If

            Dim List As IList

            If TypeOf DataSource Is IList Then
                List = TryCast(DataSource, IList)
            Else
                Dim Ilist As IListSource = TryCast(DataSource, IListSource)
                List = Ilist.GetList()
            End If

            Dim op As New List(Of Object)()
            GetAllUniqueValues(List, op)

            For Each Value As Object In op
                If Value.ToString() <> "" AndAlso re.Items(Value) Is Nothing Then
                    re.Items.Add(Value, Value.ToString())
                End If
            Next Value

            Return re
        End Function


        Public Overrides ReadOnly Property AllowItemCollectionEditor() As Boolean
            Get
                Return True
            End Get
        End Property

    End Class
End Namespace

Form1.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Linq
Imports System.Windows.Forms
Imports System.Collections.Generic

Namespace B217847Example
    Partial Public Class Form1
        Inherits Form
        Public Sub New()
            InitializeComponent()
            DataTableHelper.GetDataTable(dtTest)
        End Sub

        Private Sub OnFilterAdapterRowFilterChanged(ByVal sender As Object, ByVal e As EventArgs) Handles filterAdapter1.RowFilterChanged
            gridView1.ActiveFilterCriteria = filterAdapter1.RowCriteria
        End Sub

        Private Sub OnApplyFilterButtonClick(ByVal sender As Object, ByVal e As EventArgs) Handles simpleButton1.Click
            filterControl1.ApplyFilter()
        End Sub
    End Class
End Namespace

DataTableHelper.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Text
Imports System.Data

Namespace B217847Example
    Public Class DataTableHelper
        Public Shared Sub GetDataTable(ByVal table As DataTable)
            Dim Row1 As DataRow = table.NewRow()
            Row1("Number") = 23
            Row1("Name") = "Mike"
            Row1("Date") = New DateTime(2012, 9, 18)
            table.Rows.Add(Row1)

            Dim Row2 As DataRow = table.NewRow()
            Row2("Number") = 12
            Row2("Name") = "Jon"
            Row2("Date") = New DateTime(2012, 9, 19)
            table.Rows.Add(Row2)

            Dim Row3 As DataRow = table.NewRow()
            Row3("Number") = 1
            Row3("Name") = "Bill"
            Row3("Date") = New DateTime(2012, 9, 20)
            table.Rows.Add(Row3)

            Dim Row4 As DataRow = table.NewRow()
            Row4("Number") = 121
            Row4("Name") = "Bruce"
            Row4("Date") = New DateTime(2012, 9, 21)
            table.Rows.Add(Row4)

            Dim Row5 As DataRow = table.NewRow()
            Row5("Number") = 132
            Row5("Name") = "Lex"
            Row5("Date") = New DateTime(2012, 9, 22)
            table.Rows.Add(Row5)
        End Sub
    End Class
End Namespace

FilterAdapter.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Linq
Imports System.Collections
Imports System.ComponentModel
Imports System.Collections.Generic
Imports DevExpress.XtraEditors.Filtering
Imports DevExpress.XtraEditors.Repository
Imports DevExpress.Data.Filtering
Imports DevExpress.Data.Filtering.Helpers

Namespace B217847Example
    <ToolboxItem(True)> _
    Public Class FilterAdapter
        Inherits Component
        Implements IFilteredComponent, ISupportInitialize
        <AttributeProvider(GetType(IListSource))> _
        Public Property DataSource() As Object
            Get
                Return fDataSource
            End Get
            Set(ByVal value As Object)
                Dim oldBindingList As IBindingList = TryCast(fDataSource, IBindingList)
                If oldBindingList IsNot Nothing Then
                    RemoveHandler oldBindingList.ListChanged, AddressOf OnListChanged
                End If
                fDataSource = value
                Dim newBindingList As IBindingList = TryCast(fDataSource, IBindingList)
                If newBindingList IsNot Nothing Then
                    AddHandler newBindingList.ListChanged, AddressOf OnListChanged
                End If
            End Set
        End Property

        Private fRowCriteria As CriteriaOperator
        <Browsable(False), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)> _
        Public Overridable Property RowCriteria() As CriteriaOperator
            Get
                Return fRowCriteria
            End Get
            Set(ByVal value As CriteriaOperator)
                If ReferenceEquals(fRowCriteria, value) Then
                    Return
                End If
                fRowCriteria = value
                RaiseRowFilterChanged()
            End Set
        End Property

        Private fDataSource As Object
        Private Shared DefaultEditor As New RepositoryItemTextEdit()
        Private Shared DefaultDateEditor As New RepositoryItemDateEdit()

        Protected Overridable Function GetFilterColumns() As FilterColumnCollection
            Dim PDC As PropertyDescriptorCollection = GetProperties()
            Dim td As List(Of PropertyDescriptor) = FilterPropertyDescriptionCollection(PDC)
            Return GetFilterColumnsCollection(td)

        End Function

        Public Function GetProperties() As PropertyDescriptorCollection
            Dim list As IList = TryCast(DataSource, IList)
            If list Is Nothing Then
                If TypeOf DataSource Is IListSource Then
                    list = (CType(DataSource, IListSource)).GetList()
                End If
            End If

            If list Is Nothing Then
                Return New PropertyDescriptorCollection(New PropertyDescriptor(){}, True)
            End If

            Dim typedList As ITypedList = TryCast(list, ITypedList)
            If typedList Is Nothing Then
                If list.Count > 0 Then
                    Return TypeDescriptor.GetProperties(list(0))
                End If
            Else
                Return typedList.GetItemProperties(New PropertyDescriptor(){})
            End If
            Return New PropertyDescriptorCollection(New PropertyDescriptor(){}, True)
        End Function

        Private Shared Function FilterPropertyDescriptionCollection(ByVal PDC As PropertyDescriptorCollection) As List(Of PropertyDescriptor)
            Dim td As New List(Of PropertyDescriptor)()
            For Each pd As PropertyDescriptor In PDC
                Dim op As Object = pd.PropertyType
                If (Not pd.PropertyType.IsClass) OrElse (pd.PropertyType Is GetType(String)) Then
                    td.Add(pd)
                End If

            Next pd
            Return td
        End Function

        Private Function GetFilterColumnsCollection(ByVal td As List(Of PropertyDescriptor)) As FilterColumnCollection
            Dim filterCollection As New FilterColumnCollection()
            For Each pd As PropertyDescriptor In td

                Dim UFC As New CustomFilterColumn(pd.DisplayName, pd.Name, pd.PropertyType, GetDefaultEditor(pd.PropertyType), GetClauseClass(pd.PropertyType), Me)
                filterCollection.Add(UFC)
            Next pd
            Return filterCollection
        End Function

        Private Shared Function GetClauseClass(ByVal type As Type) As FilterColumnClauseClass
            If type Is GetType(String) Then
                Return FilterColumnClauseClass.String
            End If
            If type Is GetType(DateTime) Then
                Return FilterColumnClauseClass.DateTime
            End If
            Return FilterColumnClauseClass.Generic
        End Function

        Private Shared Function GetDefaultEditor(ByVal type As Type) As RepositoryItem
            If type Is GetType(DateTime) Then
                Return DefaultDateEditor
            End If
            Return DefaultEditor
        End Function

        Private Sub OnListChanged(ByVal sender As Object, ByVal e As ListChangedEventArgs)
            If e.ListChangedType = ListChangedType.PropertyDescriptorAdded OrElse e.ListChangedType = ListChangedType.PropertyDescriptorDeleted OrElse e.ListChangedType = ListChangedType.PropertyDescriptorChanged Then
                RaisePropertiesChanged()
            End If
        End Sub

        Protected Overrides Overloads Sub Dispose(ByVal disposing As Boolean)
            If disposing Then
                Dim oldBindingList As IBindingList = TryCast(fDataSource, IBindingList)
                If oldBindingList IsNot Nothing Then
                    RemoveHandler oldBindingList.ListChanged, AddressOf OnListChanged
                End If
            End If
            MyBase.Dispose(disposing)
        End Sub

        Public Custom Event RowFilterChanged As EventHandler Implements IFilteredComponent.RowFilterChanged
            AddHandler(ByVal value As EventHandler)
                Events.AddHandler(fRowFilterChanged, value)
            End AddHandler
            RemoveHandler(ByVal value As EventHandler)
                Events.RemoveHandler(fRowFilterChanged, value)
            End RemoveHandler
            RaiseEvent(ByVal sender As System.Object, ByVal e As System.EventArgs)
            End RaiseEvent
        End Event

        #Region "IFilteredComponent"
        Private Function CreateFilterColumnCollection() As IBoundPropertyCollection Implements IFilteredComponent.CreateFilterColumnCollection
            If Initializing Then
                Return New FilterColumnCollection()
            End If
            Return GetFilterColumns()
        End Function

        Private Shared ReadOnly fPropertiesChanged As Object = New Object()
        Private Custom Event PropertiesChanged As EventHandler Implements IFilteredComponentBase.PropertiesChanged
            AddHandler(ByVal value As EventHandler)
                Events.AddHandler(fPropertiesChanged, value)
            End AddHandler
            RemoveHandler(ByVal value As EventHandler)
                Events.RemoveHandler(fPropertiesChanged, value)
            End RemoveHandler
            RaiseEvent(ByVal sender As System.Object, ByVal e As System.EventArgs)
            End RaiseEvent
        End Event

        Private Sub RaisePropertiesChanged()
            Dim handler As EventHandler = TryCast(Events(fPropertiesChanged), EventHandler)
            If handler IsNot Nothing Then
                handler(Me, EventArgs.Empty)
            End If
        End Sub

        Private Property IFilteredComponentBase_RowCriteria() As CriteriaOperator Implements IFilteredComponentBase.RowCriteria
            Get
                Return RowCriteria
            End Get
            Set(ByVal value As CriteriaOperator)
                RowCriteria = value
            End Set
        End Property

        Private Shared ReadOnly fRowFilterChanged As Object = New Object()
        Private Custom Event mRowFilterChanged As EventHandler
            AddHandler(ByVal value As EventHandler)
                AddHandler RowFilterChanged, value
            End AddHandler
            RemoveHandler(ByVal value As EventHandler)
                RemoveHandler RowFilterChanged, value
            End RemoveHandler
            RaiseEvent(ByVal sender As System.Object, ByVal e As System.EventArgs)
            End RaiseEvent
        End Event

        Private Sub RaiseRowFilterChanged()
            Dim handler As EventHandler = TryCast(Events(fRowFilterChanged), EventHandler)
            If handler IsNot Nothing Then
                handler(Me, EventArgs.Empty)
            End If
        End Sub
        #End Region

        #Region "ISupportInitialize"
        Private Initializing As Boolean
        Private Sub BeginInit() Implements ISupportInitialize.BeginInit
            Initializing = True
        End Sub

        Private Sub EndInit() Implements ISupportInitialize.EndInit
            Initializing = False
            RaisePropertiesChanged()
        End Sub
        #End Region
    End Class
End Namespace