VB.Net/GUI/User Control

Sub class UserControl to create your own control

Imports System
Imports System.Collections
Imports System.Data
Imports System.IO
Imports System.Xml.Serialization
Imports System.Xml
Imports System.Windows.Forms
Imports System.Data.SqlClient
Imports System.Data.OleDb
Public Class MainClass
    Shared Sub Main()
        Dim form1 As Form = New Form1
        Application.Run(form1)
    End Sub
End Class



Public Class Form1
    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
    "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 MyControl1 As MyControl
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.MyControl1 = New MyControl()
        Me.SuspendLayout()
        "
        "MyControl1
        "
        Me.MyControl1.Location = New System.Drawing.Point(8, 8)
        Me.MyControl1.MessageText = "Hello, world!"
        Me.MyControl1.Name = "MyControl1"
        Me.MyControl1.Size = New System.Drawing.Size(152, 104)
        Me.MyControl1.TabIndex = 0
        "
        "Form1
        "
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(240, 189)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.MyControl1})
        Me.Name = "Form1"
        Me.ResumeLayout(False)
    End Sub
#End Region
End Class


Public Class MyControl
    Inherits System.Windows.Forms.UserControl
    Private _messageText As String
    Event HelloWorld(ByVal sender As Object, ByVal e As System.EventArgs)
#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
        MessageText = "Hello, world!"
    End Sub
    "UserControl 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 btnSayHello As System.Windows.Forms.Button
    Friend WithEvents btnSaySomething As System.Windows.Forms.Button
    Friend WithEvents btnSaySomethingElse As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.btnSayHello = New System.Windows.Forms.Button()
        Me.btnSaySomething = New System.Windows.Forms.Button()
        Me.btnSaySomethingElse = New System.Windows.Forms.Button()
        Me.SuspendLayout()
        "
        "btnSayHello
        "
        Me.btnSayHello.Location = New System.Drawing.Point(8, 8)
        Me.btnSayHello.Name = "btnSayHello"
        Me.btnSayHello.Size = New System.Drawing.Size(136, 23)
        Me.btnSayHello.TabIndex = 0
        Me.btnSayHello.Text = "Say, ""Hello, world!"""
        "
        "btnSaySomething
        "
        Me.btnSaySomething.Location = New System.Drawing.Point(8, 40)
        Me.btnSaySomething.Name = "btnSaySomething"
        Me.btnSaySomething.Size = New System.Drawing.Size(136, 23)
        Me.btnSaySomething.TabIndex = 1
        Me.btnSaySomething.Text = "Say Something"
        "
        "btnSaySomethingElse
        "
        Me.btnSaySomethingElse.Location = New System.Drawing.Point(8, 72)
        Me.btnSaySomethingElse.Name = "btnSaySomethingElse"
        Me.btnSaySomethingElse.Size = New System.Drawing.Size(136, 23)
        Me.btnSaySomethingElse.TabIndex = 2
        Me.btnSaySomethingElse.Text = "Say Something Else"
        "
        "MyControl
        "
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.btnSaySomethingElse, Me.btnSaySomething, Me.btnSayHello})
        Me.Name = "MyControl"
        Me.Size = New System.Drawing.Size(152, 104)
        Me.ResumeLayout(False)
    End Sub
#End Region
    Private Sub btnSayHello_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSayHello.Click
        " raise the event...
        RaiseEvent HelloWorld(Me, New System.EventArgs())
        MsgBox(_messageText)
    End Sub
    Private Sub btnSaySomething_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSaySomething.Click
        MsgBox("Something!")
    End Sub
    Private Sub btnSaySomethingElse_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSaySomethingElse.Click
        MsgBox("Something else!")
    End Sub
    Public Property MessageText() As String
        Get
            Return _messageText
        End Get
        Set(ByVal Value As String)
            " set the text...
            _messageText = Value
            " update the button...
            btnSayHello.Text = "Say """ & _messageText & """"
        End Set
    End Property
    Public Sub ResetMessageText()
        MessageText = "Hello, world!"
    End Sub
    Private Sub MyControl_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    End Sub
End Class

User-defined control with a timer and a label

Imports System
Imports System.Drawing
Imports System.Windows.Forms

Public Class MainClass
   Shared Sub Main()
        Dim myform As Form = New FrmClock()
        Application.Run(myform)
   End Sub " Main
End Class


Public Class FrmClock
   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
   "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
   Friend WithEvents myCClockUserControl As CClockUserControl
   
   "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.myCClockUserControl = New CClockUserControl()
      Me.SuspendLayout()
      "
      "myCClockUserControl
      "
      Me.myCClockUserControl.Location = New System.Drawing.Point(24, 24)
      Me.myCClockUserControl.Name = "myCClockUserControl"
      Me.myCClockUserControl.Size = New System.Drawing.Size(96, 48)
      Me.myCClockUserControl.TabIndex = 0
      "
      "FrmClock
      "
      Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
      Me.ClientSize = New System.Drawing.Size(144, 93)
      Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.myCClockUserControl})
      Me.Name = "FrmClock"
      Me.Text = "Clock"
      Me.ResumeLayout(False)
   End Sub
#End Region
End Class
" create a clock control that inherits from UserControl
Public Class CClockUserControl
   Inherits UserControl
#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
   "UserControl 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
   " displays time
   Friend WithEvents lblDisplay As Label
   " non-visible event-triggering timer object
   Friend WithEvents tmrClock As Timer
   "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.ruponents = New System.ruponentModel.Container()
      Me.tmrClock = New System.Windows.Forms.Timer(Me.ruponents)
      Me.lblDisplay = New System.Windows.Forms.Label()
      Me.SuspendLayout()
      "
      "tmrClock
      "
      Me.tmrClock.Enabled = True
      "
      "lblDisplay
      "
      Me.lblDisplay.Dock = System.Windows.Forms.DockStyle.Fill
      Me.lblDisplay.Font = New System.Drawing.Font("Microsoft Sans Serif", 12.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
      Me.lblDisplay.Name = "lblDisplay"
      Me.lblDisplay.Size = New System.Drawing.Size(150, 72)
      Me.lblDisplay.TabIndex = 0
      Me.lblDisplay.TextAlign = System.Drawing.ContentAlignment.MiddleCenter
      "
      "CClockUserControl
      "
      Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.lblDisplay})
      Me.Name = "CClockUserControl"
      Me.Size = New System.Drawing.Size(150, 72)
      Me.ResumeLayout(False)
   End Sub
#End Region
   " update label at every tick
   Private Sub tmrClock_Tick(ByVal sender As System.Object, _
      ByVal e As System.EventArgs) Handles tmrClock.Tick
      " get current time (Now), converto to string
      lblDisplay.Text = DateTime.Now.ToLongTimeString
   End Sub
End Class