BindingExpression Class
Contains information about a single binding within a Binding object.
System.Windows.Expression
System.Windows.Data.BindingExpressionBase
System.Windows.Data.BindingExpression
Namespace: System.Windows.Data
Assembly: System.Windows (in System.Windows.dll)
The BindingExpression type exposes the following members.
| Name | Description | |
|---|---|---|
![]() ![]() | DataItem | Gets the binding source object that this BindingExpression uses. |
![]() ![]() | ParentBinding | Returns the Binding object of the current BindingExpression. |
| 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 the Object 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.) |
![]() ![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
![]() ![]() | UpdateSource | Sends the current binding target value to the binding source property in TwoWay bindings. |
A Binding object can be used by multiple binding targets. The BindingExpression class, however, represents a single binding. You can retrieve a BindingExpression instance from a binding target by calling its FrameworkElement.GetBindingExpression method. You can then use the BindingExpression to call the UpdateSource method. This is useful to control when values are copied from the binding target to the binding source. For more information, see Data Binding.
The following code example demonstrates how to use this method.
<TextBox x:Name="textBox1" Text="{Binding Test, Mode=TwoWay, UpdateSourceTrigger=Explicit}" /> <Button Content="Update" Click="Button_Click" />
Public Class TestData Private testValue As String Public Property Test() As String Get Return testValue End Get Set(ByVal value As String) testValue = value End Set End Property End Class Private data As TestData Public Sub New() InitializeComponent() data = New TestData With data .Test = "one" End With textBox1.DataContext = data End Sub Private Sub Button_Click(ByVal sender As Object, _ ByVal e As RoutedEventArgs) Dim expression As BindingExpression = _ textBox1.GetBindingExpression(TextBox.TextProperty) MessageBox.Show("Before UpdateSource, Test = " & data.Test) expression.UpdateSource() MessageBox.Show("After UpdateSource, Test = " & data.Test) End Sub
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.



