Parameter 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.]

Defines parameters for domain service queries used by DomainDataSource.

Inheritance Hierarchy

System.Object
System.Windows.DependencyObject
System.Windows.Controls.Parameter

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

Syntax

'Declaration
Public Class Parameter _
    Inherits DependencyObject

'Usage
Dim instance As Parameter

public class Parameter : DependencyObject

public ref class Parameter : public DependencyObject

type Parameter =  
    class
        inherit DependencyObject
    end

public class Parameter extends DependencyObject

The Parameter type exposes the following members.

Constructors

	Name	Description
	Parameter	Initializes a new instance of the Parameter class.

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Properties

	Name	Description
	Dispatcher	(Inherited from DependencyObject.)
	ParameterName	Gets or sets the name of the parameter.
	Value	Gets or sets the value of the parameter.

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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
	ParameterNameProperty	Identifies the ParameterName dependency property.
	ValueProperty	Identifies the Value dependency property.

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Remarks

In some cases, a query method requires parameter values. Typically, a query method requires a parameter value to filter the data that is returned. The DomainDataSource class provides the QueryParameters collection to facilitate adding parameters. To add a parameter that uses a value from the user for the query, you bind a Parameter object to the user-input control that contains the value to use in the query and include that parameter in the QueryParameters collection.

Examples

The following example shows how to specify a value from a combo box as the parameter value.

<Grid x:Name="LayoutRoot" Background="White">
    <Grid.RowDefinitions>
        <RowDefinition Height="25" />
        <RowDefinition Height="Auto" />
    </Grid.RowDefinitions>    
    <riaControls:DomainDataSource x:Name="source" QueryName="GetProductsByColor" AutoLoad="true">
        <riaControls:DomainDataSource.DomainContext>
            <domain:ProductDomainContext />
        </riaControls:DomainDataSource.DomainContext>
        <riaControls:DomainDataSource.QueryParameters>
            <riaControls:ControlParameter 
                ParameterName="color" 
                ControlName="colorCombo" 
                PropertyName="SelectedItem.Content" 
                RefreshEventName="SelectionChanged" />
        </riaControls:DomainDataSource.QueryParameters>
    </riaControls:DomainDataSource>
    <ComboBox Width="60"  Grid.Row="0" x:Name="colorCombo">
        <ComboBoxItem Content="Black" />
        <ComboBoxItem Content="Blue" />
    </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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