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How to: Bind the Properties of Two Controls

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This example shows how to bind the property of one instantiated control to that of another using the ElementName property.

Example

The following example shows how to bind the Background property of a Canvas to the SelectedItem.Content property of a ComboBox:

<Window
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  Width="460" Height="200"
  Title="Binding the Properties of Two Controls">

  <Window.Resources>
    <Style TargetType="TextBlock">
      <Setter Property="FontSize" Value="16"/>
      <Setter Property="FontWeight" Value="Bold"/>
      <Setter Property="DockPanel.Dock" Value="Top"/>
      <Setter Property="HorizontalAlignment" Value="Center"/>
    </Style>
    <Style TargetType="Canvas">
      <Setter Property="Height" Value="50"/>
      <Setter Property="Width" Value="50"/>
      <Setter Property="Margin" Value="8"/>
      <Setter Property="DockPanel.Dock" Value="Top"/>
    </Style>
    <Style TargetType="ComboBox">
      <Setter Property="Width" Value="150"/>
      <Setter Property="Margin" Value="8"/>
      <Setter Property="DockPanel.Dock" Value="Top"/>
    </Style>
  </Window.Resources>

  <Border Margin="10" BorderBrush="Silver" BorderThickness="3" Padding="8">
    <DockPanel>
      <TextBlock>Choose a Color:</TextBlock>
      <ComboBox Name="myComboBox" SelectedIndex="0">
        <ComboBoxItem>Green</ComboBoxItem>
        <ComboBoxItem>Blue</ComboBoxItem>
        <ComboBoxItem>Red</ComboBoxItem>
      </ComboBox>
      <Canvas>
        <Canvas.Background>
          <Binding ElementName="myComboBox" Path="SelectedItem.Content"/>
        </Canvas.Background>
      </Canvas>
    </DockPanel>
  </Border>
</Window>

When this example is rendered it looks like the following:

Screenshot showing a combo box with the value green selected and a green square.

Note

The binding target property (in this example, the Background property) must be a dependency property. For more information, see Data Binding Overview.

See also