UnhandledExceptionMode Enumeración

Definición

Define a dónde debe enviar una aplicación de Windows Forms las excepciones no controladas.Defines where a Windows Forms application should send unhandled exceptions.

public enum class UnhandledExceptionMode
public enum UnhandledExceptionMode
type UnhandledExceptionMode = 
Public Enum UnhandledExceptionMode
Herencia
UnhandledExceptionMode

Campos

Automatic 0

Enrutar todas las excepciones al controlador de ThreadException, a menos que el archivo de configuración de la aplicación especifique lo contrario.Route all exceptions to the ThreadException handler, unless the application's configuration file specifies otherwise.

CatchException 2

Enrutar siempre las excepciones al controlador de ThreadException.Always route exceptions to the ThreadException handler. Omitir el archivo de configuración de la aplicación.Ignore the application configuration file.

ThrowException 1

No enrutar nunca las excepciones al controlador de ThreadException.Never route exceptions to the ThreadException handler. Omitir el archivo de configuración de la aplicación.Ignore the application configuration file.

Ejemplos

En el ejemplo de código siguiente se establecen controladores de eventos para los dos errores que se producen en Windows Forms subprocesos y errores que se producen en otros subprocesos.The following code example sets event handlers for both errors that occur on Windows Forms threads and errors that occur on other threads. Establece SetUnhandledExceptionMode de modo que la aplicación controle todos los errores, independientemente de la configuración del archivo de configuración de usuario de la aplicación.It sets SetUnhandledExceptionMode so that all errors are handled by the application, regardless of the settings in the application's user configuration file. Usa el ThreadException evento para el primero y el UnhandledException evento para el último.It uses the ThreadException event for the former, and the UnhandledException event for the latter. Puesto UnhandledException que no puede impedir que una aplicación finalice, el ejemplo simplemente registra el error en el registro de eventos del sistema antes de la terminación.Since UnhandledException cannot prevent an application from terminating, the example simply logs the error in the system Event Log prior to termination.

En este ejemplo se supone que ha definido Button dos controles button1 , button2y, en Form la clase.This sample assumes that you have defined two Button controls, button1 and button2, on your Form class.

   // Creates a class to throw the error.
public:
   ref class ErrorHandler: public System::Windows::Forms::Form
   {
      // Inserts the code to create a form with a button.

      // Programs the button to throw an exception when clicked.
   private:
      void button1_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
      {
         throw gcnew ArgumentException( "The parameter was invalid" );
      }

   public:
      static void Main()
      {
         // Creates an instance of the methods that will handle the exception.
         CustomExceptionHandler ^ eh = gcnew CustomExceptionHandler;
         
         // Adds the event handler to the event.
         Application::ThreadException += gcnew ThreadExceptionEventHandler( eh, &Form1::CustomExceptionHandler::OnThreadException );
         
         // Runs the application.
         Application::Run( gcnew ErrorHandler );
      }
   };

   // Creates a class to handle the exception event.
internal:
   ref class CustomExceptionHandler
   {
      // Handles the exception event.
   public:
      void OnThreadException( Object^ /*sender*/, ThreadExceptionEventArgs^ t )
      {
         System::Windows::Forms::DialogResult result = ::DialogResult::Cancel;
         try
         {
            result = this->ShowThreadExceptionDialog( t->Exception );
         }
         catch ( Exception^ ) 
         {
            try
            {
               MessageBox::Show( "Fatal Error", "Fatal Error", MessageBoxButtons::AbortRetryIgnore, MessageBoxIcon::Stop );
            }
            finally
            {
               Application::Exit();
            }
         }
         
         // Exits the program when the user clicks Abort.
         if ( result == ::DialogResult::Abort )
         {
            Application::Exit();
         }
      }

      // Creates the error message and displays it.
   private:
      System::Windows::Forms::DialogResult ShowThreadExceptionDialog( Exception^ e )
      {
         String^ errorMsg = "An error occurred please contact the adminstrator with the following information:\n\n";
         errorMsg = String::Concat( errorMsg, e->Message, "\n\nStack Trace:\n", e->StackTrace );
         return MessageBox::Show( errorMsg, "Application Error", MessageBoxButtons::AbortRetryIgnore, MessageBoxIcon::Stop );
      }
   };
Thread newThread = null;

// Starts the application. 
[SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.ControlAppDomain)]
public static void Main(string[] args)
{
    // Add the event handler for handling UI thread exceptions to the event.
    Application.ThreadException += new ThreadExceptionEventHandler(ErrorHandlerForm.Form1_UIThreadException);

    // Set the unhandled exception mode to force all Windows Forms errors to go through
    // our handler.
    Application.SetUnhandledExceptionMode(UnhandledExceptionMode.CatchException);

    // Add the event handler for handling non-UI thread exceptions to the event. 
    AppDomain.CurrentDomain.UnhandledException +=
        new UnhandledExceptionEventHandler(CurrentDomain_UnhandledException);

    // Runs the application.
    Application.Run(new ErrorHandlerForm());
}

// Programs the button to throw an exception when clicked.
private void button1_Click(object sender, System.EventArgs e)
{
    throw new ArgumentException("The parameter was invalid");
}

// Start a new thread, separate from Windows Forms, that will throw an exception.
private void button2_Click(object sender, System.EventArgs e)
{
    ThreadStart newThreadStart = new ThreadStart(newThread_Execute);
    newThread = new Thread(newThreadStart);
    newThread.Start();
}

// The thread we start up to demonstrate non-UI exception handling. 
void newThread_Execute()
{
    throw new Exception("The method or operation is not implemented.");
}

// Handle the UI exceptions by showing a dialog box, and asking the user whether
// or not they wish to abort execution.
private static void Form1_UIThreadException(object sender, ThreadExceptionEventArgs t)
{
    DialogResult result = DialogResult.Cancel;
    try
    {
        result = ShowThreadExceptionDialog("Windows Forms Error", t.Exception);
    }
    catch
    {
        try
        {
            MessageBox.Show("Fatal Windows Forms Error",
                "Fatal Windows Forms Error", MessageBoxButtons.AbortRetryIgnore, MessageBoxIcon.Stop);
        }
        finally
        {
            Application.Exit();
        }
    }

    // Exits the program when the user clicks Abort.
    if (result == DialogResult.Abort)
        Application.Exit();
}

// Handle the UI exceptions by showing a dialog box, and asking the user whether
// or not they wish to abort execution.
// NOTE: This exception cannot be kept from terminating the application - it can only 
// log the event, and inform the user about it. 
private static void CurrentDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
{
    try
    {
        Exception ex = (Exception)e.ExceptionObject;
        string errorMsg = "An application error occurred. Please contact the adminstrator " +
            "with the following information:\n\n";

        // Since we can't prevent the app from terminating, log this to the event log.
        if (!EventLog.SourceExists("ThreadException"))
        {
            EventLog.CreateEventSource("ThreadException", "Application");
        }

        // Create an EventLog instance and assign its source.
        EventLog myLog = new EventLog();
        myLog.Source = "ThreadException";
        myLog.WriteEntry(errorMsg + ex.Message + "\n\nStack Trace:\n" + ex.StackTrace);
    }
    catch (Exception exc)
    {
        try
        {
            MessageBox.Show("Fatal Non-UI Error",
                "Fatal Non-UI Error. Could not write the error to the event log. Reason: "
                + exc.Message, MessageBoxButtons.OK, MessageBoxIcon.Stop);
        }
        finally
        {
            Application.Exit();
        }
    }
}

// Creates the error message and displays it.
private static DialogResult ShowThreadExceptionDialog(string title, Exception e)
{
    string errorMsg = "An application error occurred. Please contact the adminstrator " +
        "with the following information:\n\n";
    errorMsg = errorMsg + e.Message + "\n\nStack Trace:\n" + e.StackTrace;
    return MessageBox.Show(errorMsg, title, MessageBoxButtons.AbortRetryIgnore,
        MessageBoxIcon.Stop);
}
Private newThread As Thread = Nothing

' Starts the application. 
<SecurityPermission(SecurityAction.Demand, Flags:=SecurityPermissionFlag.ControlAppDomain)> _
Public Shared Sub Main()
    ' Add the event handler for handling UI thread exceptions to the event.
    AddHandler Application.ThreadException, AddressOf ErrorHandlerForm.Form1_UIThreadException

    ' Set the unhandled exception mode to force all Windows Forms errors to go through
    ' our handler.
    Application.SetUnhandledExceptionMode(UnhandledExceptionMode.CatchException)

    ' Add the event handler for handling non-UI thread exceptions to the event. 
    AddHandler AppDomain.CurrentDomain.UnhandledException, AddressOf CurrentDomain_UnhandledException

    ' Runs the application.
    Application.Run(New ErrorHandlerForm())
End Sub


' Programs the button to throw an exception when clicked.
Private Sub button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles button1.Click
    Throw New ArgumentException("The parameter was invalid")
End Sub

' Start a new thread, separate from Windows Forms, that will throw an exception.
Private Sub button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles button2.Click
    Dim newThreadStart As New ThreadStart(AddressOf newThread_Execute)
    newThread = New Thread(newThreadStart)
    newThread.Start()
End Sub


' The thread we start up to demonstrate non-UI exception handling. 
Sub newThread_Execute()
    Throw New Exception("The method or operation is not implemented.")
End Sub


' Handle the UI exceptions by showing a dialog box, and asking the user whether
' or not they wish to abort execution.
Private Shared Sub Form1_UIThreadException(ByVal sender As Object, ByVal t As ThreadExceptionEventArgs)
    Dim result As System.Windows.Forms.DialogResult = _
        System.Windows.Forms.DialogResult.Cancel
    Try
        result = ShowThreadExceptionDialog("Windows Forms Error", t.Exception)
    Catch
        Try
            MessageBox.Show("Fatal Windows Forms Error", _
                "Fatal Windows Forms 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

' Handle the UI exceptions by showing a dialog box, and asking the user whether
' or not they wish to abort execution.
' NOTE: This exception cannot be kept from terminating the application - it can only 
' log the event, and inform the user about it. 
Private Shared Sub CurrentDomain_UnhandledException(ByVal sender As Object, _
ByVal e As UnhandledExceptionEventArgs)
    Try
        Dim ex As Exception = CType(e.ExceptionObject, Exception)
        Dim errorMsg As String = "An application error occurred. Please contact the adminstrator " & _
            "with the following information:" & ControlChars.Lf & ControlChars.Lf

        ' Since we can't prevent the app from terminating, log this to the event log.
        If (Not EventLog.SourceExists("ThreadException")) Then
            EventLog.CreateEventSource("ThreadException", "Application")
        End If

        ' Create an EventLog instance and assign its source.
        Dim myLog As New EventLog()
        myLog.Source = "ThreadException"
        myLog.WriteEntry((errorMsg + ex.Message & ControlChars.Lf & ControlChars.Lf & _
            "Stack Trace:" & ControlChars.Lf & ex.StackTrace))
    Catch exc As Exception
        Try
            MessageBox.Show("Fatal Non-UI Error", "Fatal Non-UI Error. Could not write the error to the event log. " & _
                "Reason: " & exc.Message, MessageBoxButtons.OK, MessageBoxIcon.Stop)
        Finally
            Application.Exit()
        End Try
    End Try
End Sub


' Creates the error message and displays it.
Private Shared Function ShowThreadExceptionDialog(ByVal title As String, ByVal e As Exception) As DialogResult
    Dim errorMsg As String = "An application error occurred. Please contact the adminstrator " & _
 "with the following information:" & ControlChars.Lf & ControlChars.Lf
    errorMsg = errorMsg & e.Message & ControlChars.Lf & _
 ControlChars.Lf & "Stack Trace:" & ControlChars.Lf & e.StackTrace

    Return MessageBox.Show(errorMsg, title, MessageBoxButtons.AbortRetryIgnore, MessageBoxIcon.Stop)
End Function

Comentarios

Utiliza esta enumeración SetUnhandledExceptionMode.This enumeration is used by SetUnhandledExceptionMode.

Nota

En la .NET Framework versión 2,0, el comportamiento de la Common Language Runtime cambió para permitir que las excepciones no controladas se propaguen hacia arriba en la pila de llamadas.In the .NET Framework version 2.0, the common language runtime behavior changed to allow unhandled exceptions to propagate up the call stack. Este comportamiento se puede deshabilitar a través del archivo de configuración de la aplicación.This behavior can be disabled via the application configuration file. Para más información, consulte Excepciones en subprocesos administrados.For more information, see Exceptions in Managed Threads.

Se aplica a