Application.ThreadException Application.ThreadException Application.ThreadException Application.ThreadException Event

定義

トラップされないスレッドの例外がスローされると、発生します。Occurs when an untrapped thread exception is thrown.

public:
 static event System::Threading::ThreadExceptionEventHandler ^ ThreadException;
public static event System.Threading.ThreadExceptionEventHandler ThreadException;
member this.ThreadException : System.Threading.ThreadExceptionEventHandler 
Public Shared Custom Event ThreadException As ThreadExceptionEventHandler 

次のコード例では、Windows フォーム スレッドと他のスレッドで発生する例外の発生する例外のイベント ハンドラーを設定します。The following code example sets event handlers for exceptions that occur on Windows Forms threads and exceptions that occur on other threads. 設定SetUnhandledExceptionModeすべての例外は、アプリケーションのユーザー構成ファイルの設定に関係なく、アプリケーションによって処理されるようにします。It sets SetUnhandledExceptionMode so that all exceptions are handled by the application, regardless of the settings in the application's user configuration file. 使用して、 ThreadException UI スレッドの例外を処理するイベントとUnhandledException非 UI スレッドの例外を処理するイベントです。It uses the ThreadException event to handle UI thread exceptions, and the UnhandledException event to handle non-UI thread exceptions. UnhandledExceptionアプリケーションを防ぐことはできませんの終了、例では、単にエラーがログに終了する前に、アプリケーション イベント ログ。Since UnhandledException cannot prevent an application from terminating, the example simply logs the error in the application event log before termination.

この例では、2 つを定義したButtonコントロール、button1button2Formクラス。This example 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

注釈

このイベントは、Windows フォーム スレッドで発生する例外を未処理のハンドルのそれ以外の場合に、Windows フォーム アプリケーションを使用します。This event allows your Windows Forms application to handle otherwise unhandled exceptions that occur in Windows Forms threads. イベント ハンドラーをアタッチ、ThreadException不明な状態でアプリケーションにそのままにこれらの例外を処理するイベントです。Attach your event handlers to the ThreadException event to deal with these exceptions, which will leave your application in an unknown state. 可能であれば、構造化例外処理ブロックで例外を処理する必要があります。Where possible, exceptions should be handled by a structured exception handling block.

このコールバックは、Windows フォーム スレッドのハンドルされない例外を設定して使用するかどうかを変更するSetUnhandledExceptionModeします。You can change whether this callback is used for unhandled Windows Forms thread exceptions by setting SetUnhandledExceptionMode. 作成していないスレッドで発生する例外をキャッチし、使用して、Windows フォームによって所有されている、UnhandledExceptionイベント ハンドラー。To catch exceptions that occur in threads not created and owned by Windows Forms, use the UnhandledException event handler.

注意

呼び出す前にこのイベントのアクティブ化が欠落しないことを保証するハンドラーをアタッチする必要がありますApplication.Runします。To guarantee that no activations of this event are missed, you must attach a handler before you call Application.Run.

注意事項

静的イベントであるため、アプリケーションが破棄されると、またはメモリ リークが発生するとき、イベント ハンドラーをデタッチする必要があります。Because this is a static event, you must detach your event handlers when your application is disposed, or memory leaks will result.

セキュリティ

SecurityPermission
このイベントにハンドラーを追加するときに、アンマネージ コードを呼び出す直前の呼び出し元。for the immediate caller to call unmanaged code when adding a handler to this event. 関連付けられた列挙体。 UnmanagedCodeAssociated enumeration: UnmanagedCode

適用対象