VB.Net Tutorial/GUI Applications/Application Exception

Application Exception

Imports System.Windows.Forms
Public Class Form1
    Inherits System.Windows.Forms.Form
    Public Sub New()
        MyBase.New()
        InitializeComponent()
    End Sub
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub
    Private components As System.ruponentModel.IContainer
    Friend WithEvents button4 As System.Windows.Forms.Button
    Friend WithEvents button3 As System.Windows.Forms.Button
    Friend WithEvents button2 As System.Windows.Forms.Button
    Friend WithEvents button1 As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.button4 = New System.Windows.Forms.Button()
        Me.button3 = New System.Windows.Forms.Button()
        Me.button2 = New System.Windows.Forms.Button()
        Me.button1 = New System.Windows.Forms.Button()
        Me.SuspendLayout()
        "
        Me.button4.Location = New System.Drawing.Point(24, 127)
        Me.button4.Name = "button4"
        Me.button4.Size = New System.Drawing.Size(144, 23)
        Me.button4.TabIndex = 7
        Me.button4.Text = "Show MessageBox"
        "
        Me.button3.Location = New System.Drawing.Point(24, 90)
        Me.button3.Name = "button3"
        Me.button3.Size = New System.Drawing.Size(144, 23)
        Me.button3.TabIndex = 6
        Me.button3.Text = "Throw Exception"
        "
        Me.button2.Location = New System.Drawing.Point(24, 53)
        Me.button2.Name = "button2"
        Me.button2.Size = New System.Drawing.Size(144, 23)
        Me.button2.TabIndex = 5
        Me.button2.Text = "Application.ExitThread"
        "
        "button1
        "
        Me.button1.Location = New System.Drawing.Point(24, 16)
        Me.button1.Name = "button1"
        Me.button1.Size = New System.Drawing.Size(144, 23)
        Me.button1.TabIndex = 4
        Me.button1.Text = "Application.Exit"
        "
        "Form1
        "
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(192, 166)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.button4, Me.button3, Me.button2, Me.button1})
        Me.Name = "Form1"
        Me.Text = "Applications"
        Me.ResumeLayout(False)
    End Sub
    Shared Sub App_Exit(ByVal sender As Object, ByVal e As EventArgs)
        System.Diagnostics.Debug.WriteLine("App_Exit")
    End Sub
    Shared Sub App_Idle(ByVal sender As Object, ByVal e As EventArgs)
        System.Diagnostics.Debug.WriteLine("App_Idle")
    End Sub
    Shared Sub App_ThreadingException(ByVal sender As Object, ByVal e As System.Threading.ThreadExceptionEventArgs)
        System.Diagnostics.Debug.WriteLine("App_ThreadException")
        Dim msg As String = "A problem has occurred in this application." & vbCrLf & vbCrLf & _
            vbTab & e.Exception.Message & vbCrLf & vbCrLf & _
            "Would you like to continue the application so that " & vbCrLf & _
            "you can save your work?"
        Dim res As DialogResult = MessageBox.Show(msg, "Unexpected Error", MessageBoxButtons.YesNo)
        If res = System.Windows.Forms.DialogResult.Yes Then Exit Sub
        Application.Exit()
    End Sub
    Shared Sub DumpThreadID(ByVal name As String)
        System.Diagnostics.Debug.WriteLine(name & " thread id= " & System.AppDomain.GetCurrentThreadId().ToString())
    End Sub
    Shared Sub DummyThreadStart()
        DumpThreadID("Dummy Thread")
        AddHandler Application.ThreadExit, New EventHandler(AddressOf App_ThreadExit)
    End Sub
    Shared Sub Main()
        AddHandler Application.ThreadException, New System.Threading.ThreadExceptionEventHandler(AddressOf App_ThreadingException)
        AddHandler Application.Idle, New EventHandler(AddressOf App_Idle)
        AddHandler Application.ThreadExit, New EventHandler(AddressOf App_ThreadExit)
        AddHandler Application.ApplicationExit, New EventHandler(AddressOf App_Exit)
        DumpThreadID("UI Thread")
        Dim dummythread As System.Threading.Thread = New System.Threading.Thread(New System.Threading.ThreadStart(AddressOf DummyThreadStart))
        dummythread.Start()
        Application.Run(New Form1())
    End Sub
    Shared Sub App_ThreadExit(ByVal sender As Object, ByVal e As EventArgs)
        System.Diagnostics.Debug.WriteLine("App_ThreadExit on thread id= " & System.AppDomain.GetCurrentThreadId().ToString())
    End Sub
    Private Sub button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button1.Click
        Application.Exit()
    End Sub
    Private Sub button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button2.Click
        Application.ExitThread()
    End Sub
    Private Sub button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button3.Click
        Throw New System.IO.FileLoadException()
    End Sub
End Class

Catch Application Level Exception

Imports System.Drawing
Imports System.IO
Imports System.Windows.Forms
Imports System.Math
public class ApplicationLevelException
   public Shared Sub Main
         Application.Run(New Form1)
   End Sub
End class

Public Class Form1
    " Install the ThreadException event handler.
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        AddHandler Application.ThreadException, AddressOf Me.app_ThreadException
    End Sub
    " Catch a ThreadException event.
    Private Sub app_ThreadException(ByVal sender As Object, ByVal e As System.Threading.ThreadExceptionEventArgs)
        MessageBox.Show("Caught unhandled exception")
    End Sub
    " Throw an InvalidDataException.
    Private Sub btnThrow_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnThrow.Click
        Throw New InvalidDataException("Bad data! Bad!")
    End Sub
    " Call the OnThreadException method.
    Private Sub btnOnThreadException_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOnThreadException.Click
        Application.OnThreadException(New InvalidDataException("Bad data! Bad!"))
    End Sub
End Class
<Global.Microsoft.VisualBasic.rupilerServices.DesignerGenerated()> _
Partial Public Class Form1
    Inherits System.Windows.Forms.Form
    "Form overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()> _
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing AndAlso components IsNot Nothing Then
            components.Dispose()
        End If
        MyBase.Dispose(disposing)
    End Sub
    "Required by the Windows Form Designer
    Private components As System.ruponentModel.IContainer
    "NOTE: The following procedure is required by the Windows Form Designer
    "It can be modified using the Windows Form Designer.  
    "Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.btnThrow = New System.Windows.Forms.Button
        Me.btnOnThreadException = New System.Windows.Forms.Button
        Me.SuspendLayout()
        "
        "btnThrow
        "
        Me.btnThrow.Location = New System.Drawing.Point(26, 24)
        Me.btnThrow.Name = "btnThrow"
        Me.btnThrow.Size = New System.Drawing.Size(104, 24)
        Me.btnThrow.TabIndex = 2
        Me.btnThrow.Text = "Throw"
        "
        "btnOnThreadException
        "
        Me.btnOnThreadException.Location = New System.Drawing.Point(162, 24)
        Me.btnOnThreadException.Name = "btnOnThreadException"
        Me.btnOnThreadException.Size = New System.Drawing.Size(104, 24)
        Me.btnOnThreadException.TabIndex = 3
        Me.btnOnThreadException.Text = "OnThreadException"
        "
        "Form1
        "
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(292, 73)
        Me.Controls.Add(Me.btnThrow)
        Me.Controls.Add(Me.btnOnThreadException)
        Me.Name = "Form1"
        Me.Text = "CatchThreadException"
        Me.ResumeLayout(False)
    End Sub
    Friend WithEvents btnThrow As System.Windows.Forms.Button
    Friend WithEvents btnOnThreadException As System.Windows.Forms.Button
End Class