Occurs when an exception that is raised by Silverlight is not handled.
Assembly: System.Windows (in System.Windows.dll)
By default, Silverlight will detect and process unhandled exceptions that are raised from any part of the Silverlight application. If you would prefer to perform unhandled exception detection and processing, you can handle the event, which is raised by Application for each thrown exception that is unhandled by application code.
The event handler is passed a ApplicationUnhandledExceptionEventArgs object, which stores a reference to the unhandled exception in its ExceptionObject property. You can use this information to determine whether an exception is recoverable or not.
When you detect and process an unhandled exception and you do not want Silverlight to continue processing it, you have to set the Handled property to true. If you leave the Handled property set to false when exiting the handler, the unmanaged exception handling as registered for the onError event takes place for the unhandled exception. An onError handler can also be handled by managed code, if you marshal the handler.
The following example shows how to handle and use the event.
Imports System.IO Partial Public Class App Inherits Application Public Sub New() InitializeComponent() End Sub Private Sub Application_Startup(ByVal o As Object, _ ByVal e As StartupEventArgs) Handles Me.Startup Me.RootVisual = New Page() End Sub Private Sub Application_UnhandledException(ByVal sender As Object, _ ByVal e As ApplicationUnhandledExceptionEventArgs) Handles Me.UnhandledException If TypeOf e.ExceptionObject Is FileNotFoundException Then ' Inform the user ' Recover from the error e.Handled = True Return End If ' Exception is unrecoverable so stop the application and allow the ' Silverlight plug-in control to detect and process the exception. End Sub End Class
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.