Статья
11/18/2011

ApplicationUnhandledExceptionEventArgs Class

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Provides data for the Application.UnhandledException event.

Inheritance Hierarchy

System.Object
System.EventArgs
System.Windows.ApplicationUnhandledExceptionEventArgs

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

Syntax

'Declaration
Public Class ApplicationUnhandledExceptionEventArgs _
    Inherits EventArgs

public class ApplicationUnhandledExceptionEventArgs : EventArgs

The ApplicationUnhandledExceptionEventArgs type exposes the following members.

Constructors

	Name	Description
	ApplicationUnhandledExceptionEventArgs	Initializes a new instance of the ApplicationUnhandledExceptionEventArgs class.

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Properties

	Name	Description
	ExceptionObject	Gets or sets the unhandled exception.
	Handled	Gets or sets a value that indicates whether the exception is handled.

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Methods

	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.)

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Remarks

Application.UnhandledException uses the generic EventHandler<TEventArgs> and this ApplicationUnhandledExceptionEventArgs class for event data.

The ExceptionObject property provides information about the unhandled exception. Set the Handled property to true to prevent additional processing of the exception after your UnhandledException handler completes.

Examples

The following example shows how to handle and use the UnhandledException 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

using System.IO; // FileNotFoundException
using System.Windows; // Application, StartupEventArgs, ApplicationUnhandledExceptionEventArgs

namespace SilverlightApplication
{
    public partial class App : Application
    {
        public App()
        {
            this.Startup += this.Application_Startup;
            this.UnhandledException += this.Application_UnhandledException;

            InitializeComponent();
        }

        private void Application_Startup(object sender, StartupEventArgs e)
        {
            this.RootVisual = new Page();
        }

        private void Application_UnhandledException(object sender, 
            ApplicationUnhandledExceptionEventArgs e)
        {
            if (e.ExceptionObject is FileNotFoundException)
            {
                // Inform the user

                // Recover from the error
                e.Handled = true;
                return;
            }

            // Exception is unrecoverable so stop the application and allow the 
            // Silverlight plug-in control to detect and process the exception.
        }
    }
}

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

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

Platforms

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

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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