VB.Net/GUI/User Control
Sub class UserControl to create your own control
<source lang="vbnet"> 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
</source>
User-defined control with a timer and a label
<source lang="vbnet"> 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
</source>
