Application.SetUnhandledExceptionMode Metoda
Definicja
Ważne
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Instruuje aplikację, jak reagować na nieobsługiwane wyjątki.
Przeciążenia
SetUnhandledExceptionMode(UnhandledExceptionMode) |
Instruuje aplikację, jak reagować na nieobsługiwane wyjątki. |
SetUnhandledExceptionMode(UnhandledExceptionMode, Boolean) |
Instruuje aplikację, jak reagować na nieobsługiwane wyjątki, opcjonalnie stosując zachowanie specyficzne dla wątku. |
Przykłady
Poniższy przykład kodu ustawia procedury obsługi zdarzeń dla wyjątków występujących w Windows Forms wątkach i wyjątkach występujących w innych wątkach. SetUnhandledExceptionMode Ustawia tak, aby wszystkie wyjątki są obsługiwane przez aplikację, niezależnie od ustawień w pliku konfiguracji użytkownika aplikacji. Używa zdarzenia do obsługi wyjątków wątków interfejsu ThreadException użytkownika i UnhandledException zdarzenia do obsługi wyjątków wątków innych niż interfejs użytkownika. Ponieważ UnhandledException nie można zapobiec zakończeniu działania aplikacji, przykład po prostu rejestruje błąd w dzienniku zdarzeń aplikacji przed zakończeniem.
W tym przykładzie założono, że zdefiniowano dwie Button kontrolki button1
i button2
, w klasie Form .
// 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.
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
SetUnhandledExceptionMode(UnhandledExceptionMode)
Instruuje aplikację, jak reagować na nieobsługiwane wyjątki.
public:
static void SetUnhandledExceptionMode(System::Windows::Forms::UnhandledExceptionMode mode);
public static void SetUnhandledExceptionMode (System.Windows.Forms.UnhandledExceptionMode mode);
static member SetUnhandledExceptionMode : System.Windows.Forms.UnhandledExceptionMode -> unit
Public Shared Sub SetUnhandledExceptionMode (mode As UnhandledExceptionMode)
Parametry
UnhandledExceptionMode Wartość opisująca, jak aplikacja powinna zachowywać się, jeśli wyjątek jest zgłaszany bez przechwycenia.
Wyjątki
Nie można ustawić trybu wyjątku po utworzeniu pierwszego okna przez aplikację.
Przykłady
Poniższy przykład kodu ustawia procedury obsługi zdarzeń dla wyjątków występujących w Windows Forms wątkach i wyjątkach występujących w innych wątkach. SetUnhandledExceptionMode Ustawia tak, aby wszystkie wyjątki są obsługiwane przez aplikację, niezależnie od ustawień w pliku konfiguracji użytkownika aplikacji. Używa zdarzenia do obsługi wyjątków wątków interfejsu ThreadException użytkownika i UnhandledException zdarzenia do obsługi wyjątków wątków innych niż interfejs użytkownika. Ponieważ UnhandledException nie można zapobiec zakończeniu działania aplikacji, przykład po prostu rejestruje błąd w dzienniku zdarzeń aplikacji przed zakończeniem.
W tym przykładzie założono, że zdefiniowano dwie Button kontrolki button1
i button2
, w klasie Form .
// 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.
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
Uwagi
Często nie jest możliwe przechwycenie wszystkich wyjątków zgłaszanych przez Windows Forms. Korzystając z tej metody, możesz poinstruować aplikację, czy powinna przechwytywać wszystkie nieobsługiwane wyjątki zgłoszone przez składniki Windows Forms i kontynuować działanie, czy też powinna uwidocznić je użytkownikowi i zatrzymać wykonywanie.
Wywołaj metodę SetUnhandledExceptionMode przed utworzeniem wystąpienia głównej Run formy aplikacji przy użyciu metody .
Aby przechwytywać wyjątki występujące w wątkach, które nie zostały utworzone i należące do Windows Forms, użyj UnhandledException procedury obsługi zdarzeń.
Zobacz też
Dotyczy
SetUnhandledExceptionMode(UnhandledExceptionMode, Boolean)
Instruuje aplikację, jak reagować na nieobsługiwane wyjątki, opcjonalnie stosując zachowanie specyficzne dla wątku.
public:
static void SetUnhandledExceptionMode(System::Windows::Forms::UnhandledExceptionMode mode, bool threadScope);
public static void SetUnhandledExceptionMode (System.Windows.Forms.UnhandledExceptionMode mode, bool threadScope);
static member SetUnhandledExceptionMode : System.Windows.Forms.UnhandledExceptionMode * bool -> unit
Public Shared Sub SetUnhandledExceptionMode (mode As UnhandledExceptionMode, threadScope As Boolean)
Parametry
UnhandledExceptionMode Wartość opisująca, jak aplikacja powinna zachowywać się, jeśli wyjątek jest zgłaszany bez przechwycenia.
- threadScope
- Boolean
true
aby ustawić tryb wyjątku wątku; w przeciwnym razie , false
.
Wyjątki
Nie można ustawić trybu wyjątku po utworzeniu pierwszego okna przez aplikację.
Przykłady
Poniższy przykład kodu ustawia procedury obsługi zdarzeń dla wyjątków występujących w Windows Forms wątkach i wyjątkach występujących w innych wątkach. SetUnhandledExceptionMode Ustawia tak, aby wszystkie wyjątki są obsługiwane przez aplikację, niezależnie od ustawień w pliku konfiguracji użytkownika aplikacji. Używa zdarzenia do obsługi wyjątków wątków interfejsu ThreadException użytkownika i UnhandledException zdarzenia do obsługi wyjątków wątków innych niż interfejs użytkownika. Ponieważ UnhandledException nie można zapobiec zakończeniu działania aplikacji, przykład po prostu rejestruje błąd w dzienniku zdarzeń aplikacji przed zakończeniem.
W tym przykładzie założono, że zdefiniowano dwie Button kontrolki button1
i button2
, w klasie Form .
// 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.
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
Uwagi
Często nie jest możliwe przechwycenie wszystkich wyjątków zgłaszanych przez Windows Forms. Korzystając z tej metody, możesz poinstruować aplikację, czy powinna przechwytywać wszystkie nieobsługiwane wyjątki zgłoszone przez składniki Windows Forms i kontynuować działanie, czy też powinna uwidocznić je użytkownikowi i zatrzymać wykonywanie.
Wywołaj metodę SetUnhandledExceptionMode przed utworzeniem wystąpienia głównej Run formy aplikacji przy użyciu metody .
Gdy threadScope
jest true
to , tryb wyjątku wątku jest ustawiony. Tryb wyjątku wątku zastępuje tryb wyjątku aplikacji, jeśli mode
nie jest ustawiony na Automaticwartość .
Gdy threadScope
jest false
to , jest ustawiony tryb wyjątku aplikacji. Tryb wyjątku aplikacji jest używany dla wszystkich wątków, które mają Automatic tryb. Ustawienie trybu wyjątku aplikacji nie ma wpływu na ustawienie bieżącego wątku.
Aby przechwytywać wyjątki występujące w wątkach, które nie zostały utworzone i należące do Windows Forms, użyj UnhandledException procedury obsługi zdarzeń.