Binding Class

Definition

/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
class Binding : BindingBase

[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
public class Binding : BindingBase

Public Class Binding
Inherits BindingBase

<Binding .../>
- or -
<dependencyobject dependencyproperty="{Binding bindingArgs}" />

Inheritance

Object IInspectable DependencyObject BindingBase Binding

Attributes

ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

Windows requirements

Examples

The following code example demonstrates how to create a binding in XAML. For the complete code listing, see the XAML data binding sample.

<StackPanel Margin="5">

  <TextBlock Text="Name:" Style="{StaticResource DescriptionTextStyle}" 
    Margin="5" HorizontalAlignment="Left" VerticalAlignment="Top"/>

  <TextBox Text="{Binding Path=Name, Mode=TwoWay}" 
    Width="350" Margin="5" HorizontalAlignment="Left" VerticalAlignment="Top"/>

  <TextBlock Text="Organization:" Style="{StaticResource DescriptionTextStyle}" 
    Margin="5" HorizontalAlignment="Left" VerticalAlignment="Top"/>

  <!-- You can omit the 'Path=' portion of the binding expression. --> 
  <TextBox Text="{Binding Organization, Mode=TwoWay}" Width="350" 
    Margin="5" HorizontalAlignment="Left" VerticalAlignment="Top"/>

</StackPanel>

The following example code demonstrates how to create a binding in code.

// Create the source string.
string s = "Hello";

// Create the binding description.
Binding b = new Binding();
b.Mode = BindingMode.OneTime;
b.Source = s;

// Attach the binding to the target.
TextBlock MyText = new TextBlock();
MyText.SetBinding(TextBlock.TextProperty, b);

// Create the source string.
String^ s = ref new String(L"Hello");

// Create the binding description.
Binding^ b = ref new Binding();
b->Mode = BindingMode::OneTime;
b->Source = s;

// Attach the binding to the target.
TextBlock^ MyText = ref new TextBlock();
MyText->SetBinding(MyText->TextProperty, b);

'Create the source string 
Dim s As String = "Hello"

'Create the binding description 
Dim b As New Binding()
b.Mode = BindingMode.OneTime
b.Source = s

'Attach the binding to the target 
Dim MyText As New TextBlock()
MyText.SetBinding(TextBlock.TextProperty, b)

Remarks

The {Binding} markup extension enables you to specify a Binding value as a single attribute string in XAML, including setting Binding properties such as Path and Source. For more info about data binding concepts, see Data binding in depth.

The Binding class might be considered the code-behind exposure of the {Binding} markup extension. If a binding is already applied to a target (which happens when the XAML is loaded), you can't set the read-write properties of a Binding object to change how a binding behaves at run-time. Any XAML-defined binding should be considered immutable. But you can create a new Binding object, set its properties, and establish a new binding on a specific UI element target using FrameworkElement.SetBinding. For more info, see Creating bindings in code.

A Binding object connects a dependency property of a FrameworkElement directly to a data object so that updates to the data object are automatically propagated to the property that uses data binding. The Binding class defines the properties of a binding. Each binding must have a target element, target property, and data source, although some values are provided by default if you don't specify them.

To bind to a property or a sub-property on a data object, set the Path property of the Binding object. For more info on how to set Path in code or in XAML, see Property-path syntax or {Binding} markup extension.

You can apply an instance of a Binding class to multiple targets. However, you cannot modify the property values of a Binding object after you attach it to a target element.

For more info on XAML attribute usage for properties that can take a Binding, or that can otherwise be set to a data-bound value, see {Binding} markup extension.

The property that is the target of a data binding must be a dependency property. For more info, see Dependency properties overview.

Constructors

Properties

Methods

Applies to

See also

• SetBinding(DependencyObject, DependencyProperty, BindingBase)
• XAML data binding sample
• Data binding in depth
• Dependency properties overview
• Property-path syntax