ThreadExceptionEventArgs Class
Assembly: System (in system.dll)
A ThreadExceptionEventArgs is created by a thread when an unhandled exception occurs. ThreadExceptionEventArgs contains the Exception that occurred.
The following example allows you to raise a ThreadException event by clicking button1 on a form. The example creates two classes. The ErrorHandler class creates the form and the button that raises the event. The CustomExceptionHandler class provides the methods to handle the exception.
In Main in the ErrorHandler class, the code creates a new instance of the exception handling class, that is, an instance of the CustomExceptionHandler. Then the instance is added to the event, and the application is run.
In the OnThreadException method in the CustomExceptionHandler class, the example uses a try...catch...finally statement to process the exception. The ShowThreadExceptionDialog method creates the message to display, and displays it in a message box.
' Creates a class to throw the error. Public Class ErrorHandler Inherits System.Windows.Forms.Form ' Inserts code to create a form with a button. ' Programs the button to throw the exception when clicked. Private Sub button1_Click(sender As Object, e As System.EventArgs) Throw New ArgumentException("The parameter was invalid") End Sub Public Shared Sub Main() ' Creates an instance of the methods that will handle the exception. Dim eh As New CustomExceptionHandler() ' Adds the event handler to to the event. AddHandler Application.ThreadException, AddressOf eh.OnThreadException ' Runs the application. Application.Run(New ErrorHandler()) End Sub End Class ' Creates a class to handle the exception event. Friend Class CustomExceptionHandler 'Handles the exception event Public Sub OnThreadException(sender As Object, t As ThreadExceptionEventArgs) Dim result As DialogResult = DialogResult.Cancel Try result = Me.ShowThreadExceptionDialog(t.Exception) Catch Try MessageBox.Show("Fatal Error", "Fatal Error", _ MessageBoxButtons.AbortRetryIgnore, MessageBoxIcon.Stop) Finally Application.Exit() End Try End Try ' Exits the program when the user clicks Abort. If result = DialogResult.Abort Then Application.Exit() End If End Sub ' Creates the error message and display it. Private Function ShowThreadExceptionDialog(e As Exception) As DialogResult Dim errorMsg As String = "An error occurred please contact the " & _ "adminstrator with the following information:" & _ Microsoft.VisualBasic.ControlChars.Cr & _ Microsoft.VisualBasic.ControlChars.Cr errorMsg &= e.Message & Microsoft.VisualBasic.ControlChars.Cr & _ Microsoft.VisualBasic.ControlChars.Cr & "Stack Trace:" & _ Microsoft.VisualBasic.ControlChars.Cr & e.StackTrace Return MessageBox.Show(errorMsg, "Application Error", _ MessageBoxButtons.AbortRetryIgnore, MessageBoxIcon.Stop) End Function End Class
System.EventArgs
System.Threading.ThreadExceptionEventArgs
Microsoft.VisualBasic.ApplicationServices.UnhandledExceptionEventArgs
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.