RelativeSource Class
Implements a markup extension that describes the location of the binding source relative to the position of the binding target.
Assembly: PresentationFramework (in PresentationFramework.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
The RelativeSource type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | RelativeSource() | Initializes a new instance of the RelativeSource class. |
![]() | RelativeSource(RelativeSourceMode) | Initializes a new instance of the RelativeSource class with an initial mode. |
![]() | RelativeSource(RelativeSourceMode, Type, Int32) | Initializes a new instance of the RelativeSource class with an initial mode and additional tree-walking qualifiers for finding the desired relative source. |
| Name | Description | |
|---|---|---|
![]() | AncestorLevel | Gets or sets the level of ancestor to look for, in FindAncestor mode. Use 1 to indicate the one nearest to the binding target element. |
![]() | AncestorType | Gets or sets the type of ancestor to look for. |
![]() | Mode | Gets or sets a RelativeSourceMode value that describes the location of the binding source relative to the position of the binding target. |
![]() ![]() | PreviousData | Gets a static value that is used to return a RelativeSource constructed for the PreviousData mode. |
![]() ![]() | Self | Gets a static value that is used to return a RelativeSource constructed for the Self mode. |
![]() ![]() | TemplatedParent | Gets a static value that is used to return a RelativeSource constructed for the TemplatedParent mode. |
| Name | Description | |
|---|---|---|
![]() | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() | GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | ProvideValue | Returns an object that should be set as the value on the target object's property for this markup extension. For RelativeSource, this is another RelativeSource, using the appropriate source for the specified mode. (Overrides MarkupExtension::ProvideValue(IServiceProvider).) |
![]() | ShouldSerializeAncestorLevel | Indicates whether the AncestorLevel property should be persisted. |
![]() | ShouldSerializeAncestorType | Indicates whether the AncestorType property should be persisted. |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
| Name | Description | |
|---|---|---|
![]() ![]() | ISupportInitialize::BeginInit | This member supports the Windows Presentation Foundation (WPF) infrastructure and is not intended to be used directly from your code. |
![]() ![]() | ISupportInitialize::EndInit | This member supports the Windows Presentation Foundation (WPF) infrastructure and is not intended to be used directly from your code. |
One of the ways to specify a binding source is to use the Binding::RelativeSource property. This is the property type of that property. RelativeSource is simultaneously a markup extension implementation and a data object. When the extension returns itself (see ProvideValue), the relevant information is contained in the data. The main purpose of the markup extension is to allow a variable-argument constructor syntax in attribute form, so that the FindAncestor mode can be defined inline with the two extra arguments for ancestor type and level that the other modes do not require.
For XAML information, see RelativeSource MarkupExtension.
The following example shows a style trigger that creates a ToolTip that reports a validation error message. Using the RelativeSource property, the value of the setter binds to the error content of the current TextBox (the TextBox using the style). For more information on this example, see How to: Implement Binding Validation.
<Style x:Key="textBoxInError" TargetType="{x:Type TextBox}"> <Style.Triggers> <Trigger Property="Validation.HasError" Value="true"> <Setter Property="ToolTip" Value="{Binding RelativeSource={x:Static RelativeSource.Self}, Path=(Validation.Errors)[0].ErrorContent}"/> </Trigger> </Style.Triggers> </Style>
The following example shows the Style definition of a custom control called NumericUpDown. The Text property of the TextBlock is bound to the Value of the object that is the TemplatedParent, which is the NumericUpDown control that this Style is applied to in this case.
<!--ControlTemplate for NumericUpDown that inherits from Control.--> <Style TargetType="{x:Type local:NumericUpDown}"> <Setter Property="HorizontalAlignment" Value="Center"/> <Setter Property="VerticalAlignment" Value="Center"/> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type local:NumericUpDown}"> <Grid Margin="3"> <Grid.RowDefinitions> <RowDefinition/> <RowDefinition/> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition/> <ColumnDefinition/> </Grid.ColumnDefinitions> <Border BorderThickness="1" BorderBrush="Gray" Margin="2" Grid.RowSpan="2" VerticalAlignment="Center" HorizontalAlignment="Stretch"> <TextBlock Text="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Value}" Width="60" TextAlignment="Right" Padding="5"/> </Border> <RepeatButton Command="{x:Static local:NumericUpDown.IncreaseCommand}" Grid.Column="1" Grid.Row="0">Up</RepeatButton> <RepeatButton Command="{x:Static local:NumericUpDown.DecreaseCommand}" Grid.Column="1" Grid.Row="1">Down</RepeatButton> </Grid> </ControlTemplate> </Setter.Value> </Setter> </Style>
For the complete sample, see NumericUpDown Custom Control with Theme and UI Automation Support Sample.
The following returns the second ItemsControl encountered on the upward path starting at the target element of the binding.
More Code
| How to: Create ListViewItems with a CheckBox | This example shows how to display a column of CheckBox controls in a ListView control that uses a GridView. |
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
