TextBox.OnLostFocus Method

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Called before LostFocus event occurs.

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


Protected Overrides Sub OnLostFocus ( _
    e As RoutedEventArgs _
protected override void OnLostFocus(
    RoutedEventArgs e



The OnLostFocus method is called before any event handler for the LostFocus event is called. This method allows derived classes to handle the LostFocus event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

By default, when the TextBox control has the focus, the text in the TextBox is selected and the cursor appears.

Notes to Inheritors

When overriding OnLostFocus method in a derived class, be sure to call the base class’s OnLostFocus method so that registered delegates receive the event.

Version Information


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.