ThreadExceptionEventArgs Classe

Definição

public ref class ThreadExceptionEventArgs : EventArgs

public class ThreadExceptionEventArgs : EventArgs

type ThreadExceptionEventArgs = class
    inherit EventArgs

Public Class ThreadExceptionEventArgs
Inherits EventArgs

Herança

Object

EventArgs

ThreadExceptionEventArgs

Derivado

Microsoft.VisualBasic.ApplicationServices.UnhandledExceptionEventArgs

Exemplos

O exemplo seguinte permite-lhe criar um ThreadException evento clicando button1 num formulário. O exemplo cria duas classes. A ErrorHandler classe cria o formulário e o botão que levanta o evento. A CustomExceptionHandler classe fornece os métodos para lidar com a exceção.

Em Main na ErrorHandler classe, o código cria uma nova instância da classe de tratamento de exceções, ou seja, uma instância do CustomExceptionHandler. Depois, a instância é adicionada ao evento e a aplicação é executada.

No OnThreadException método da CustomExceptionHandler classe, o exemplo usa uma try...catch...finally instrução para processar a exceção. O ShowThreadExceptionDialog método cria a mensagem para mostrar e apresenta-a numa caixa de mensagem.

using System;
using System.Threading;
using System.Windows.Forms;

// Create a form with a button that, when clicked, throws an exception.
 public class ErrorForm : System.Windows.Forms.Form
 {
    internal Button button1;

    public ErrorForm() : base()
    {
       // Add the button to the form.
       this.button1 = new System.Windows.Forms.Button();
       this.SuspendLayout();
       this.button1.Location = new System.Drawing.Point(100, 43);
       this.button1.Size = new System.Drawing.Size(75, 23);
       this.button1.Text = "Click!";
       this.Controls.Add(this.button1);
       this.button1.Click += new EventHandler(this.button1_Click);

       this.Text = "ThreadException";
       this.ResumeLayout(false);
    }

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

    public static void Main()
    {
       // Add the event handler.
       Application.ThreadException += new ThreadExceptionEventHandler(CustomExceptionHandler.OnThreadException);

       // Start the example.
       Application.Run(new ErrorForm());
    }
 }

 // Create a class to handle the exception event.
 internal class CustomExceptionHandler
 {
     // Handle the exception event
    public static void OnThreadException(object sender, ThreadExceptionEventArgs t)
    {
       DialogResult result = ShowThreadExceptionDialog(t.Exception);

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

    // Create and display the error message.
    private static DialogResult ShowThreadExceptionDialog(Exception e)
    {
       string errorMsg = "An error occurred.  Please contact the adminstrator " +
            "with the following information:\n\n";
       errorMsg += string.Format("Exception Type: {0}\n\n", e.GetType().Name);
       errorMsg += "\n\nStack Trace:\n" + e.StackTrace;
       return MessageBox.Show(errorMsg, "Application Error",
            MessageBoxButtons.AbortRetryIgnore, MessageBoxIcon.Stop);
    }
 }

Imports System.Threading
Imports System.Windows.Forms

' Create a form with a button that, when clicked, throws an exception.
Public Class ErrorForm : Inherits Form
    Friend WithEvents button1 As Button

    Public Sub New()
       ' Add the button to the form.
      Me.button1 = New System.Windows.Forms.Button()
      Me.SuspendLayout()
      Me.button1.Location = New System.Drawing.Point(100, 43)
      Me.button1.Size = New System.Drawing.Size(75, 23)
      Me.button1.Text = "Click!"
      Me.Controls.Add(Me.button1)

      Me.Text = "ThreadException"
      Me.ResumeLayout(False)
   End Sub

    ' Throw an exception when the button is clicked.
    Private Sub button1_Click(sender As Object, e As System.EventArgs) _
                Handles button1.Click
        Throw New ArgumentException("The parameter was invalid.")
    End Sub
    
    Public Shared Sub Main()
        ' Add the event handler.
        AddHandler Application.ThreadException,
                   AddressOf CustomExceptionHandler.OnThreadException
        
        ' Start the example.
        Application.Run(New ErrorForm())
    End Sub
End Class

' Create a class to handle the exception event.
Friend Class CustomExceptionHandler
    'Handle the exception event.
    Public Shared Sub OnThreadException(sender As Object, t As ThreadExceptionEventArgs)
        Dim result As DialogResult = ShowThreadExceptionDialog(t.Exception)

        ' Exit the program when the user clicks Abort.
        If result = DialogResult.Abort Then
            Application.Exit()
        End If
    End Sub
     
    ' Create and display the error message.
    Private Shared Function ShowThreadExceptionDialog(e As Exception) As DialogResult
        Dim errorMsg As String = "An error occurred.  Please contact the " &
            "adminstrator with the following information:" &
            vbCrLf & vbCrLf
        errorMsg &= "Exception Type: " & e.GetType().Name & vbCrLf & vbCrLf
        errorMsg &= e.Message & vbCrLf & vbCrLf
        errorMsg &= "Stack Trace: " & vbCrLf & e.StackTrace

        Return MessageBox.Show(errorMsg, "Application Error",
               MessageBoxButtons.AbortRetryIgnore, MessageBoxIcon.Stop)
    End Function
End Class

Observações

A ThreadExceptionEventArgs é criado por um thread quando ocorre uma exceção não tratada. ThreadExceptionEventArgs contém o Exception que ocorreu.

Ver também

• Thread
• ThreadStart
• ThreadExceptionEventHandler