VB.Net Tutorial/GUI/Control Event
A simple event handler
<source lang="vbnet">Imports System.Windows.Forms public class GenericEventHandler
public Shared Sub Main Application.Run(New FrmSimple) End Sub
End class
Public Class FrmSimple
Inherits System.Windows.Forms.Form
- 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 " New " 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 " Dispose Friend WithEvents lblOutput As System.Windows.Forms.Label " Required by the Windows Form Designer Private components As System.ruponentModel.Container " 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.lblOutput = New System.Windows.Forms.Label() Me.SuspendLayout() " "lblOutput " Me.lblOutput.Location = New System.Drawing.Point(16, 16) Me.lblOutput.Name = "lblOutput" Me.lblOutput.Size = New System.Drawing.Size(152, 80) Me.lblOutput.TabIndex = 0 Me.lblOutput.Text = "Click Me!" Me.lblOutput.TextAlign = System.Drawing.ContentAlignment.MiddleCenter " "FrmSimple " Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13) Me.ClientSize = New System.Drawing.Size(176, 101) Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.lblOutput}) Me.Name = "FrmSimple" Me.Text = "SimpleEventExample" Me.ResumeLayout(False) End Sub
- End Region
Private Sub lblOutput_Click(ByVal sender As Object, _ ByVal e As System.EventArgs) Handles lblOutput.Click MessageBox.Show("Label was clicked") End Sub
End Class</source>
Handle multiple event handlers from different controls
<source lang="vbnet">Imports System.Windows.Forms public class HandleMultipleEventsFromDifferentControls
public Shared Sub Main Application.Run(New Form1) End Sub
End class Public Class Form1
Private Sub MultipleEvents(ByVal sender As Object, _ ByVal e As System.EventArgs) Handles _ TextBox1.Enter, TextBox2.Enter, TextBox3.Enter, _ TextBox1.TextChanged, TextBox2.TextChanged, TextBox3.TextChanged Dim activeControl As TextBox activeControl = CType(sender, TextBox) ShowInfo.Text = "TextField #" & _ activeControl.Name & _ ", " & activeControl.Text.Length & " character(s)" End Sub
End Class
<Global.Microsoft.VisualBasic.rupilerServices.DesignerGenerated()> _ Partial Class Form1
Inherits System.Windows.Forms.Form "Form overrides dispose to clean up the component list. <System.Diagnostics.DebuggerNonUserCode()> _ Protected 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.TextBox1 = New System.Windows.Forms.TextBox Me.Label1 = New System.Windows.Forms.Label Me.Label2 = New System.Windows.Forms.Label Me.TextBox2 = New System.Windows.Forms.TextBox Me.Label3 = New System.Windows.Forms.Label Me.TextBox3 = New System.Windows.Forms.TextBox Me.Label4 = New System.Windows.Forms.Label Me.ShowInfo = New System.Windows.Forms.Label Me.SuspendLayout() " "TextBox1 " Me.TextBox1.Location = New System.Drawing.Point(120, 8) Me.TextBox1.Name = "TextBox1" Me.TextBox1.Size = New System.Drawing.Size(160, 20) Me.TextBox1.TabIndex = 1 " "Label1 " Me.Label1.AutoSize = True Me.Label1.Location = New System.Drawing.Point(8, 10) Me.Label1.Name = "Label1" Me.Label1.Size = New System.Drawing.Size(93, 13) Me.Label1.TabIndex = 0 Me.Label1.Text = "Text Box Field #1:" " "Label2 " Me.Label2.AutoSize = True Me.Label2.Location = New System.Drawing.Point(8, 42) Me.Label2.Name = "Label2" Me.Label2.Size = New System.Drawing.Size(93, 13) Me.Label2.TabIndex = 2 Me.Label2.Text = "Text Box Field #2:" " "TextBox2 " Me.TextBox2.Location = New System.Drawing.Point(120, 40) Me.TextBox2.Name = "TextBox2" Me.TextBox2.Size = New System.Drawing.Size(160, 20) Me.TextBox2.TabIndex = 3 " "Label3 " Me.Label3.AutoSize = True Me.Label3.Location = New System.Drawing.Point(9, 72) Me.Label3.Name = "Label3" Me.Label3.Size = New System.Drawing.Size(93, 13) Me.Label3.TabIndex = 4 Me.Label3.Text = "Text Box Field #3:" " "TextBox3 " Me.TextBox3.Location = New System.Drawing.Point(121, 70) Me.TextBox3.Name = "TextBox3" Me.TextBox3.Size = New System.Drawing.Size(159, 20) Me.TextBox3.TabIndex = 5 " "Label4 " Me.Label4.AutoSize = True Me.Label4.Location = New System.Drawing.Point(8, 104) Me.Label4.Name = "Label4" Me.Label4.Size = New System.Drawing.Size(62, 13) Me.Label4.TabIndex = 6 Me.Label4.Text = "Information:" " "ShowInfo " Me.ShowInfo.AutoSize = True Me.ShowInfo.Location = New System.Drawing.Point(120, 104) Me.ShowInfo.Name = "ShowInfo" Me.ShowInfo.Size = New System.Drawing.Size(27, 13) Me.ShowInfo.TabIndex = 7 Me.ShowInfo.Text = "N/A" " "Form1 " Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!) Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font Me.ClientSize = New System.Drawing.Size(320, 136) Me.Controls.Add(Me.ShowInfo) Me.Controls.Add(Me.Label4) Me.Controls.Add(Me.Label3) Me.Controls.Add(Me.TextBox3) Me.Controls.Add(Me.Label2) Me.Controls.Add(Me.TextBox2) Me.Controls.Add(Me.Label1) Me.Controls.Add(Me.TextBox1) Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle Me.MaximizeBox = False Me.Name = "Form1" Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen Me.Text = "Sharing Control Logic" Me.ResumeLayout(False) Me.PerformLayout() End Sub Friend WithEvents TextBox1 As System.Windows.Forms.TextBox Friend WithEvents Label1 As System.Windows.Forms.Label Friend WithEvents Label2 As System.Windows.Forms.Label Friend WithEvents TextBox2 As System.Windows.Forms.TextBox Friend WithEvents Label3 As System.Windows.Forms.Label Friend WithEvents TextBox3 As System.Windows.Forms.TextBox Friend WithEvents Label4 As System.Windows.Forms.Label Friend WithEvents ShowInfo As System.Windows.Forms.Label
End Class</source>