VB.Net Tutorial/Event/AddHandler

Add general to Label using AddHandler lblTitle.Click, AddressOf GenericEvent

<source lang="vbnet">Imports System.Windows.Forms public class GeneralEventLabel

  public Shared Sub Main
       Application.Run(New Form1)
  End Sub

End class Public Class Form1

   Inherits System.Windows.Forms.Form

1. Region " Windows Form Designer generated code "

   Public Sub New()
       MyBase.New()
       "This call is required by the Windows Form Designer.
       InitializeComponent()
       "Add any initialization after the InitializeComponent() call
   End Sub
   "Form overrides dispose to clean up the component list.
   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
   "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.
   Friend WithEvents lblTitle As System.Windows.Forms.Label
   Friend WithEvents btnTest As System.Windows.Forms.Button
   <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
       Me.lblTitle = New System.Windows.Forms.Label()
       Me.btnTest = New System.Windows.Forms.Button()
       Me.SuspendLayout()
       "
       "lblTitle
       "
       Me.lblTitle.Location = New System.Drawing.Point(40, 32)
       Me.lblTitle.Name = "lblTitle"
       Me.lblTitle.Size = New System.Drawing.Size(150, 25)
       Me.lblTitle.TabIndex = 0
       Me.lblTitle.Text = "Events Demonstrator"
       AddHandler lblTitle.Click, AddressOf GenericEvent

       "
       "btnTest
       "
       Me.btnTest.Location = New System.Drawing.Point(40, 96)
       Me.btnTest.Name = "btnTest"
       Me.btnTest.TabIndex = 1
       Me.btnTest.Text = "Do It!"
       "
       "Form1
       "
       Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
       Me.ClientSize = New System.Drawing.Size(242, 173)
       Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.btnTest, Me.lblTitle})
       Me.Name = "Form1"
       Me.Text = "Events Demonstrator"
       Me.ResumeLayout(False)
   End Sub

1. End Region

   Private Sub btnTest_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnTest.Click
       MessageBox.Show("Click event just handled.", "Event Demo")
   End Sub
   Private Sub lblTitle_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lblTitle.Click
       MessageBox.Show("Click event just handled.", "Event Demo")
   End Sub
   Private Sub GenericEvent(ByVal sender As System.Object, _
                            ByVal e As System.EventArgs)
       MessageBox.Show("Generic dynamic event just handled.", "Event Demo")
   End Sub

End Class</source>

AddHandler btn.Click, AddressOf btn_Click

<source lang="vbnet">imports System imports System.Drawing imports System.Windows.Forms public class AddressOfEvent : inherits System.Windows.Forms.Form

 Private WithEvents btn as Button
 public sub New()
   btn = new Button()
   btn.Location = new Point(50,50)
   btn.Text = "Test"
   Controls.Add(btn)
       AddHandler btn.Click, AddressOf btn_Click
 end sub
 public shared sub Main() 
   Application.Run(new AddressOfEvent())
 end sub
 private sub btn_Click(ByVal sender as object, _
     ByVal e as EventArgs)
   MessageBox.Show("btn_Click method","Events Demonstration")
 end sub
 private sub btn_ClickHandles(ByVal sender as object, _
     ByVal e as EventArgs) _
     Handles btn.Click
   MessageBox.Show("btn_ClickHandles method","Events Demonstration")
 end sub

end class</source>

Events Demonstration - AddHandler

<source lang="vbnet">imports System imports System.Drawing imports System.Windows.Forms public class EventsDemo : inherits System.Windows.Forms.Form

 Private btn as Button
 public sub New()
   btn = new Button()
   btn.Location = new Point(50,50)
   btn.Text = "Test"
   Controls.Add(btn)
       AddHandler btn.Click, AddressOf btn_Click
 end sub
 public shared sub Main() 
   Application.Run(new EventsDemo())
 end sub
 private sub btn_Click(ByVal sender as object,ByVal e as EventArgs)
   MessageBox.Show("btn_Click method","Events Demonstration")
 end sub

end class</source>

Use AddHandler to add event handler to a button

<source lang="vbnet">Imports System.Drawing Imports System.Drawing.Drawing2D Imports System.Windows.Forms public class AddButtonToForm

  public Shared Sub Main
       Application.Run(New Form1)
  End Sub

End class Public Class Form1

   Inherits System.Windows.Forms.Form

1. Region " Windows Form Designer generated code "

   Public Sub New()
       MyBase.New()
       "This call is required by the Windows Form Designer.
       InitializeComponent()
       "Add any initialization after the InitializeComponent() call
   End Sub
   "Form overrides dispose to clean up the component list.
   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
   "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.
   Friend WithEvents Button1 As System.Windows.Forms.Button
   Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
   <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
       Me.Button1 = New System.Windows.Forms.Button
       Me.TextBox1 = New System.Windows.Forms.TextBox
       Me.SuspendLayout()
       "
       "Button1
       "
       Me.Button1.Location = New System.Drawing.Point(104, 56)
       Me.Button1.Name = "Button1"
       Me.Button1.TabIndex = 0
       Me.Button1.Text = "Click Me"
       "
       "TextBox1
       "
       Me.TextBox1.Location = New System.Drawing.Point(96, 168)
       Me.TextBox1.Name = "TextBox1"
       Me.TextBox1.TabIndex = 1
       Me.TextBox1.Text = ""
       "
       "Form1
       "
       Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
       Me.ClientSize = New System.Drawing.Size(292, 273)
       Me.Controls.Add(Me.TextBox1)
       Me.Controls.Add(Me.Button1)
       Me.Name = "Form1"
       Me.Text = "Form1"
       Me.ResumeLayout(False)
   End Sub

1. End Region

   Dim WithEvents Button2 As Button
   Private Sub Button1_Click(ByVal sender As System.Object, _
       ByVal e As System.EventArgs) Handles Button1.Click
       Button2 = New Button
       Button2.Location = New Point(104, 104)
       Button2.Size = New Size(75, 23)
       Button2.Text = "And Me!"
       AddHandler Button2.Click, AddressOf Button2_Clicked
       Controls.Add(Button2)
   End Sub
   Private Sub Button2_Clicked(ByVal sender As Object, ByVal e As System.EventArgs)
       TextBox1.Text = "No problem!"
   End Sub

End Class</source>