UnhandledExceptionMode 列舉

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

定義 Windows Form 應用程式應將未處理之例外狀況 (Exception) 傳送至何處。

C#

public enum UnhandledExceptionMode

繼承

Object

ValueType

Enum

UnhandledExceptionMode

欄位

名稱	值	Description
Automatic	0	除非應用程式的組態檔中另有指定，否則會將所有的例外狀況傳送至 ThreadException 處理常式。
CatchException	2	一直會將例外狀況傳送至 ThreadException 處理常式。 忽略應用程式組態檔。
ThrowException	1	一定不要將例外狀況傳送至 ThreadException 處理常式。 忽略應用程式組態檔。

範例

下列程式碼範例會針對Windows Forms執行緒上發生的錯誤，以及在其他執行緒上發生的錯誤，設定事件處理常式。 它會設定 SetUnhandledExceptionMode ，讓應用程式處理所有錯誤，而不論應用程式的使用者組態檔中的設定為何。 它會針對前者使用 ThreadException 事件，以及 UnhandledException 後者的事件。 由於 UnhandledException 無法防止應用程式終止，因此範例只會在終止之前，在系統事件記錄檔中記錄錯誤。

此範例假設您已在 類別上 Form 定義兩 Button 個控制項 button1 和 button2 。

C#

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);
}

備註

這個列舉是由 SetUnhandledExceptionMode 使用。

注意

在 .NET Framework 2.0 版中，Common Language Runtime 行為已變更為允許未處理的例外狀況傳播呼叫堆疊。 您可以透過應用程式組態檔停用此行為。 如需詳細資訊，請參閱受控執行緒中的例外狀況。

適用於