FilterBehavior Class

Allows you to use the Filter Editor / Filter Elements to filter data-bound controls that do not provide a filtering UI (for example, Charts and Data Editors).

Namespace: DevExpress.Xpf.Core.FilteringUI

Assembly: DevExpress.Xpf.Grid.v19.2.dll

Declaration

C#

public class FilterBehavior :
    Behavior<FrameworkElement>

VB.NET

Public Class FilterBehavior
    Inherits Behavior(Of FrameworkElement)

Remarks

Filter Elements and ChartControl

Tip

Demo: FilterBehavior - Chart Filtering

Requires a WPF Subscription. Download

The following code sample shows how to use the FilterBehavior to make the Filter Elements work with the ChartControl.

1. Add the FilterBehavior to the behaviors of a container that holds the Filter Elements. The FilterBehavior automatically specifies the FilterElement.Context properties.
2. Specify the FilterBehavior.ItemsSource property to allow the Filter Elements to get unique filter values.
3. Specify the FilterBehavior.Fields property to configure edit settings.
4. Bind a data-bound control’s filter criteria to the FilterBehavior.ActualFilterCriteria object.

Xaml

<dxa:AccordionControl>
    <dxmvvm:Interaction.Behaviors>
        <dxfui:FilterBehavior x:Name="filterBehavior" 
                              ItemsSource="{Binding ElementName=chart, Path=DataSource}">
            <dxfui:FilterField FieldName="Company">
                <dxe:ComboBoxEditSettings ItemsSource="{Binding Companies}"/>
            </dxfui:FilterField>
        </dxfui:FilterBehavior>
    </dxmvvm:Interaction.Behaviors>
    <dxa:AccordionItem Header="Year" IsExpanded="True">
        <dxfui:RangeFilterElement FieldName="Year"/>
    </dxa:AccordionItem>
    <dxa:AccordionItem Header="Company" IsExpanded="True">
        <dxfui:CheckedListFilterElement FieldName="Company"/>
    </dxa:AccordionItem>
</dxa:AccordionControl>
<!-- -->
<dxc:ChartControl Name="chart" DataSource="{Binding Sales}">
    <dxc:XYDiagram2D SeriesDataMember="Company">
        <!-- -->
        <dxc:XYDiagram2D.SeriesTemplate>
            <dxc:BarFullStackedSeries2D Name="seriesTemplate" 
                                        ArgumentDataMember="Year" ValueDataMember="Sales"
                                        FilterCriteria="{Binding ElementName=filterBehavior, 
                                                                 Path=ActualFilterCriteria}">
            </dxc:BarFullStackedSeries2D>
        </dxc:XYDiagram2D.SeriesTemplate>
    </dxc:XYDiagram2D>
</dxc:ChartControl>   

Filter Elements and Data Editors

Tip

Demo: FilterBehavior - ListBoxEdit Filtering

Requires a WPF Subscription. Download

The following code sample shows how to use the FilterBehavior to make the Filter Elements work with the ListBoxEdit.

1. Add the FilterBehavior to the behaviors of a container that holds the Filter Elements. The FilterBehavior automatically specifies the FilterElement.Context properties.
2. Specify the FilterBehavior.ItemsSource property to allow the Filter Elements to get unique filter values.
3. Specify the FilterBehavior.Fields property to configure edit settings and predefined filters.
4. Bind a data-bound control’s filter criteria to the FilterBehavior.ActualFilterCriteria object.

Xaml

<dxa:AccordionControl>
    <dxmvvm:Interaction.Behaviors>
        <dxfui:FilterBehavior x:Name="filterBehavior" 
                              ItemsSource="{Binding ElementName=listBoxEdit, Path=ItemsSource}">
            <dxfui:FilterField FieldName="CategoryName">
                <dxe:ComboBoxEditSettings ItemsSource="{Binding Categories}"/>
            </dxfui:FilterField>
            <dxfui:FilterField FieldName="UnitsInStock">
                <dxfui:FilterField.PredefinedFilters>
                    <dxfui:PredefinedFilterCollection>
                        <dxfui:PredefinedFilter Filter="?p > 0" Name="In stock" />
                        <dxfui:PredefinedFilter Filter="?p = 0" Name="Out of stock" />
                    </dxfui:PredefinedFilterCollection>
                </dxfui:FilterField.PredefinedFilters>
            </dxfui:FilterField>
        </dxfui:FilterBehavior>
    </dxmvvm:Interaction.Behaviors>
    <dxfui:CheckedListFilterElement FieldName="CategoryName" />
    <dxfui:PredefinedFiltersElement FieldName="UnitsInStock" />
    <dxfui:CheckBoxFilterElement FieldName="Discontinued" />
</dxa:AccordionControl> 
<!-- -->
<dxe:ListBoxEdit Name="listBoxEdit" ItemsSource="{Binding Products}"
                 FilterCriteria="{Binding ElementName=filterBehavior, Path=ActualFilterCriteria}"/>

Filter Elements and CollectionView

Tip

Demo: FilterBehavior - CollectionView Filtering

Requires a WPF Subscription. Download

The following code sample shows how to use the FilterBehavior to make the Filter Elements work with the Collectionview.

1. Add the FilterBehavior to the behaviors of a container that holds the Filter Elements. The FilterBehavior automatically specifies the FilterElement.Context properties.
2. Specify the FilterBehavior.ItemsSource property to allow the Filter Elements to get unique filter values.
3. Specify the FilterBehavior.Fields property to configure edit settings.
4. The FilterBehavior creates the FilterBehavior.ActualFilterCriteria object. Use the FilterBehavior.ActualFilterCriteria object to filter data in code.

Xaml

<dxa:AccordionControl>
    <dxmvvm:Interaction.Behaviors>
        <dxfui:FilterBehavior  x:Name="filterBehavior" 
                               ItemsSource="{Binding ElementName=listBoxEdit, Path=ItemsSource.SourceCollection}">
            <dxfui:FilterField FieldName="CategoryName">
                <dxe:ComboBoxEditSettings ItemsSource="{Binding Categories}"/>
            </dxfui:FilterField>
        </dxfui:FilterBehavior>
        <local:CollectionViewFilterBehavior 
            CollectionView="{Binding ElementName=listBoxEdit, Path=ItemsSource}"
            FilterCriteria="{Binding ElementName=filterBehavior, Path=ActualFilterCriteria}"/>
    </dxmvvm:Interaction.Behaviors>
    <dxfui:CheckedListFilterElement FieldName="CategoryName"/>
    <dxfui:CheckBoxFilterElement FieldName="Discontinued"/>
</dxa:AccordionControl>
<!-- -->
<ListBox Name="listBoxEdit" ItemsSource="{Binding ProductsView}">
    <!-- -->
</ListBox> 

C#

public class CollectionViewFilterBehavior : Behavior<FrameworkElement> {
    public ICollectionView CollectionView {
        get { return (ICollectionView)GetValue(CollectionViewProperty); }
        set { SetValue(CollectionViewProperty, value); }
    }
    public static readonly DependencyProperty CollectionViewProperty =
        DependencyProperty.Register("CollectionView", typeof(ICollectionView), typeof(CollectionViewFilterBehavior), 
            new PropertyMetadata(null, (o, e) => ((CollectionViewFilterBehavior)o).UpdateCollectionView()));

    public CriteriaOperator FilterCriteria {
        get { return (CriteriaOperator)GetValue(FilterCriteriaProperty); }
        set { SetValue(FilterCriteriaProperty, value); }
    }
    public static readonly DependencyProperty FilterCriteriaProperty =
        DependencyProperty.Register("FilterCriteria", typeof(CriteriaOperator), typeof(CollectionViewFilterBehavior), 
            new PropertyMetadata(null, (o, e) => ((CollectionViewFilterBehavior)o).UpdateCollectionView()));

    void UpdateCollectionView() {
        if(CollectionView == null)
            return;
        var elementType = ListBindingHelper.GetListItemType(CollectionView.SourceCollection);
        var method = GetType()
            .GetMethod("ApplyFilter", BindingFlags.Instance | BindingFlags.NonPublic)
            .MakeGenericMethod(new[] { elementType });
        method.Invoke(this, null);
    }
    void ApplyFilter<T>() {
        var converter = new GridFilterCriteriaToExpressionConverter<T>();
        var expression = converter.Convert(FilterCriteria);
        var filter = expression.Compile();
        CollectionView.Filter = x => filter((T)x);
    }
}

VB.NET

Public Class CollectionViewFilterBehavior
    Inherits Behavior(Of FrameworkElement)

    Public Property CollectionView As ICollectionView
        Get
            Return CType(GetValue(CollectionViewProperty), ICollectionView)
        End Get
        Set(ByVal value As ICollectionView)
            SetValue(CollectionViewProperty, value)
        End Set
    End Property

    Public Shared ReadOnly CollectionViewProperty As DependencyProperty = DependencyProperty.Register("CollectionView", GetType(ICollectionView), GetType(CollectionViewFilterBehavior), New PropertyMetadata(Nothing, Function(o, e) (CType(o, CollectionViewFilterBehavior)).UpdateCollectionView()))

    Public Property FilterCriteria As CriteriaOperator
        Get
            Return CType(GetValue(FilterCriteriaProperty), CriteriaOperator)
        End Get
        Set(ByVal value As CriteriaOperator)
            SetValue(FilterCriteriaProperty, value)
        End Set
    End Property

    Public Shared ReadOnly FilterCriteriaProperty As DependencyProperty = DependencyProperty.Register("FilterCriteria", GetType(CriteriaOperator), GetType(CollectionViewFilterBehavior), New PropertyMetadata(Nothing, Function(o, e) (CType(o, CollectionViewFilterBehavior)).UpdateCollectionView()))

    Private Sub UpdateCollectionView()
        If CollectionView Is Nothing Then Return
        Dim elementType = ListBindingHelper.GetListItemType(CollectionView.SourceCollection)
        Dim method = [GetType]().GetMethod("ApplyFilter", BindingFlags.Instance Or BindingFlags.NonPublic).MakeGenericMethod({elementType})
        method.Invoke(Me, Nothing)
    End Sub

    Private Sub ApplyFilter(Of T)()
        Dim converter = New GridFilterCriteriaToExpressionConverter(Of T)()
        Dim expression = converter.Convert(FilterCriteria)
        Dim filter = expression.Compile()
        CollectionView.Filter = Function(x) filter(CType(x, T))
    End Sub
End Class 

ViewModel Data Filtering

Tip

Demo: FilterBehavior - ViewModel Data Filtering

Requires a WPF Subscription. Download

The following code sample shows how to use the FilterBehavior to make the Filter Elements filter the ViewModel data.

1. Add the FilterBehavior to the behaviors of a container that holds the Filter Elements. The FilterBehavior automatically specifies the FilterElement.Context properties.
2. Specify the FilterBehavior.ItemsSource property to allow the Filter Elements to get unique filter values.
3. Specify the FilterBehavior.Fields property to configure edit settings.
4. The FilterBehavior creates the FilterBehavior.ActualFilterCriteria object. Use the FilterBehavior.ActualFilterCriteria object to filter data in code.

Xaml

<dxa:AccordionControl>
    <dxmvvm:Interaction.Behaviors>
        <dxfui:FilterBehavior x:Name="filterBehavior" 
                              ActualFilterCriteriaChanged="filterBehavior_ActualFilterCriteriaChanged">
            <dxfui:FilterField FieldName="CategoryName">
                <dxe:ComboBoxEditSettings ItemsSource="{Binding Categories}"/>
            </dxfui:FilterField>
        </dxfui:FilterBehavior>
    </dxmvvm:Interaction.Behaviors>
    <dxfui:CheckedListFilterElement FieldName="CategoryName" />
    <dxfui:CheckBoxFilterElement FieldName="Discontinued" />
    <!-- -->
</dxa:AccordionControl>
<!-- -->
<dxe:ListBoxEdit Name="listBoxEdit" ItemsSource="{Binding Products}">
    <!-- -->
</dxe:ListBoxEdit> 

C#

void filterBehavior_ActualFilterCriteriaChanged(object sender, EventArgs e) {
    var viewModel = (FilterBehaviorServerDataViewModel)DataContext;
    if(ReferenceEquals(filterBehavior.ActualFilterCriteria, null)) {
        viewModel.SetFilter(null);
    } else {
        var converter = new GridFilterCriteriaToExpressionConverter<ProductInfo>();
        var expression = converter.Convert(filterBehavior.ActualFilterCriteria);
        viewModel.SetFilter(expression);
    }
}

VB.NET

Private Sub filterBehavior_ActualFilterCriteriaChanged(ByVal sender As Object, ByVal e As EventArgs)
    Dim viewModel = CType(DataContext, FilterBehaviorServerDataViewModel)

    If ReferenceEquals(filterBehavior.ActualFilterCriteria, Nothing) Then
        viewModel.SetFilter(Nothing)
    Else
        Dim converter = New GridFilterCriteriaToExpressionConverter(Of ProductInfo)()
        Dim expression = converter.Convert(filterBehavior.ActualFilterCriteria)
        viewModel.SetFilter(expression)
    End If
End Sub 

Standalone Filter Editor

Tip

Demo: FilterBehavior - Standalone Filter Editor

Requires a WPF Subscription. Download

The following code sample shows how to use the FilterBehavior to make the Filter Editor work with the ChartControl.

1. Add the FilterBehavior to the behaviors of the Filter Editor. The FilterBehavior automatically specifies the FilterEditorControl.Context property.
2. Specify the FilterBehavior.ItemsSource property to allow the Filter Editor to get unique filter values.
3. Specify the FilterBehavior.Fields property to configure display fields.
4. Bind a data-bound control’s filter criteria to the FilterBehavior.ActualFilterCriteria object.

Xaml

<Button Name="ApplyFilterButton" Content="Apply Filter"
        Command="{Binding Commands.ApplyFilter, ElementName=filterEditor}"/>
<!-- -->
<dxfui:FilterEditorControl x:Name="filterEditor">
    <dxmvvm:Interaction.Behaviors>
        <dxfui:FilterBehavior x:Name="filterBehavior" 
                              FilterString="[Year] >= 2014 And Sales > 1"
                              ItemsSource="{Binding ElementName=chart, Path=DataSource}">
            <dxfui:FilterField FieldName="Company"/>
            <dxfui:FilterField FieldName="Year"/>
            <dxfui:FilterField FieldName="Sales" Caption="Sales, millions of USD"/>
            <dxfui:FilterField FieldName="Charges" Caption="Charges, millions of USD"/>
        </dxfui:FilterBehavior>
    </dxmvvm:Interaction.Behaviors>
</dxfui:FilterEditorControl> 
<!-- -->
<dxc:ChartControl Name="chart" DataSource="{Binding Sales}">
    <dxc:XYDiagram2D SeriesDataMember="Company">
        <!-- -->
        <dxc:XYDiagram2D.SeriesTemplate>
            <dxc:BarFullStackedSeries2D Name="seriesTemplate"
                ArgumentDataMember="Year" ValueDataMember="Sales"
                FilterCriteria="{Binding ElementName=filterBehavior, Path=ActualFilterCriteria}">
            </dxc:BarFullStackedSeries2D>
        </dxc:XYDiagram2D.SeriesTemplate>
    </dxc:XYDiagram2D>
</dxc:ChartControl>   

Specify Filter Criteria in Code

Use the FilterString / FilterCriteria property to create a filter expression that consists of multiple conditions applied to multiple columns, and apply it to the FilterBehavior. Setting the FilterString / FilterCriteria property to a new value clears any filters that have been previously applied.

FilterString Property

Xaml

<dxfui:FilterBehavior x:Name="filterBehavior" FilterString="[Year] >= 2014 And Sales > 1"
                      ItemsSource="{Binding ElementName=chart, Path=DataSource}">
    <!-- -->
</dxfui:FilterBehavior>

FilterCriteria Property

Xaml

<dxfui:FilterBehavior x:Name="filterBehavior" 
                      ItemsSource="{Binding ElementName=chart, Path=DataSource}">
    <!-- -->                    
</dxfui:FilterBehavior> 

C#

filterBehavior.FilterCriteria = (
    new BinaryOperator("Year", 2014, BinaryOperatorType.GreaterOrEqual) & 
    new BinaryOperator("Sales", 1, BinaryOperatorType.Greater)
); 

VB.NET

filterBehavior.FilterCriteria = (
    New BinaryOperator("Year", 2014, BinaryOperatorType.GreaterOrEqual) And 
    New BinaryOperator("Sales", 1, BinaryOperatorType.Greater)
)

Inheritance

Object

DispatcherObject

DependencyObject

Freezable

Animatable

DevExpress.Mvvm.UI.Interactivity.AttachableObjectBase

DevExpress.Mvvm.UI.Interactivity.Behavior

DevExpress.Mvvm.UI.Interactivity.Behavior<FrameworkElement>

FilterBehavior