FilterDescriptor Class

Article
01/27/2012

[WCF RIA Services Version 1 Service Pack 2 is compatible with either .NET framework 4 or .NET Framework 4.5, and with either Silverlight 4 or Silverlight 5.]

Represents a filter description for query operations in a DomainDataSource object.

Inheritance Hierarchy

System.Object
System.Windows.DependencyObject
System.Windows.Controls.FilterDescriptor

Namespace: System.Windows.Controls
Assembly: System.Windows.Controls.DomainServices (in System.Windows.Controls.DomainServices.dll)

Syntax

'Declaration
Public Class FilterDescriptor _
    Inherits DependencyObject

'Usage
Dim instance As FilterDescriptor

public class FilterDescriptor : DependencyObject

public ref class FilterDescriptor : public DependencyObject

type FilterDescriptor =  
    class
        inherit DependencyObject
    end

public class FilterDescriptor extends DependencyObject

The FilterDescriptor type exposes the following members.

Constructors

	Name	Description
	FilterDescriptor()	Initializes a new instance of the FilterDescriptor class with default values.
	FilterDescriptor(String, FilterOperator, Object)	Initializes a new instance of the FilterDescriptor class with the specified property to use for filtering, the operator to use when evaluating the filtering check, and the filter value.

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Properties

	Name	Description
	Dispatcher	(Inherited from DependencyObject.)
	IgnoredValue	Gets or sets the value that is not applied to a query operation for filtering.
	IsCaseSensitive	Gets or sets a value indicating whether the FilterDescriptor is case sensitive for string values.
	Operator	Gets or sets the filter operator.
	PropertyPath	Gets or sets the name of the property path used as the data value to assess whether the entity meets the filter check.
	Value	Gets or sets the value to use for evaluating the filter condition.

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Methods

	Name	Description
	CheckAccess	(Inherited from DependencyObject.)
	ClearValue	(Inherited from DependencyObject.)
	Equals	(Inherited from Object.)
	Finalize	(Inherited from Object.)
	GetAnimationBaseValue	(Inherited from DependencyObject.)
	GetHashCode	(Inherited from Object.)
	GetType	(Inherited from Object.)
	GetValue	(Inherited from DependencyObject.)
	MemberwiseClone	(Inherited from Object.)
	ReadLocalValue	(Inherited from DependencyObject.)
	SetValue	(Inherited from DependencyObject.)
	ToString	(Inherited from Object.)

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Fields

	Name	Description
	DefaultIgnoredValue	The default value of the IgnoredValue property.
	IgnoredValueProperty	Identifies the IgnoredValue dependency property.
	IsCaseSensitiveProperty	Identifies the IsCaseSensitive dependency property.
	OperatorProperty	Identifies the Operator dependency property.
	PropertyPathProperty	Identifies the PropertyPath dependency property.
	ValueProperty	Identifies the Value dependency property.

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Remarks

The DomainDataSource control provides the FilterDescriptors collection to enable you to filter the data that is returned by the query. By adding filters, you can specify that only entities which meet the condition in the filter are loaded from the domain context. You define the logical relationship between different filters by setting the FilterOperator property on the DomainDataSource object. The FilterOperator property supports any value in the FilterDescriptorLogicalOperator enumerator.Within a FilterDescriptor instance, you set the Operator property to specify the type of comparison to use when filtering. Filter descriptors support the operations in the FilterOperator enumerator.

Examples

The following example shows two filter descriptors that are connected by a logical AND statement. One filter depends on user input and one filter is specified in the declarative syntax.

<Grid x:Name="LayoutRoot" Background="White">  
    <Grid.RowDefinitions>
        <RowDefinition Height="25" />
        <RowDefinition Height="Auto" />
    </Grid.RowDefinitions>
    <riaControls:DomainDataSource x:Name="source" QueryName="GetProducts" AutoLoad="true">
        <riaControls:DomainDataSource.DomainContext>
            <domain:ProductDomainContext />
        </riaControls:DomainDataSource.DomainContext>   
        <riaControls:DomainDataSource.FilterDescriptors>
            <riaData:FilterDescriptorCollection LogicalOperator="And">
              <riaData:FilterDescriptor PropertyPath="Color" Operator="IsEqualTo" Value="Blue" />
              <riaData:FilterDescriptor PropertyPath="ListPrice" Operator="IsLessThanOrEqualTo">
                  <riaControls:ControlParameter 
                      ControlName="MaxPrice" 
                      PropertyName="SelectedItem.Content" 
                      RefreshEventName="SelectionChanged" />
              </riaData:FilterDescriptor>
            </riaData:FilterDescriptorCollection>
        </riaControls:DomainDataSource.FilterDescriptors>
    </riaControls:DomainDataSource>
    <ComboBox x:Name="MaxPrice" Grid.Row="0" Width="60" SelectedIndex="0">
        <ComboBoxItem Content="100" />
        <ComboBoxItem Content="500" />
        <ComboBoxItem Content="1000" />
    </ComboBox>
    <data:DataGrid Grid.Row="1" ItemsSource="{Binding Data, ElementName=source}" />
</Grid>

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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