The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

BindingExpression.UpdateSource Method

Sends the current binding target value to the binding source property in TwoWay bindings.

Namespace:  System.Windows.Data
Assembly:  System.Windows (in System.Windows.dll)

public void UpdateSource()


The BindingExpression is detached from the binding target.

You can use this method to control when the data source is updated. This is useful, for example, to validate several controls together before you update their data sources.

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
    public String Test { get; set; }

TestData data;

public MainPage()
    data = new TestData { Test = "one" };
    textBox1.DataContext = data;

private void Button_Click(object sender, RoutedEventArgs e)
    BindingExpression expression = textBox1.GetBindingExpression(TextBox.TextProperty);
    MessageBox.Show("Before UpdateSource, Test = " + data.Test);
    MessageBox.Show("After UpdateSource, Test = " + data.Test);


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Was this page helpful?
(1500 characters remaining)
Thank you for your feedback

Community Additions

© 2015 Microsoft