Inherit TextBox to create custom control based on TextBox : TextBox « GUI « VB.Net Tutorial

1. VB.Net Tutorial
2. GUI
3. TextBox

Imports System
Imports System.Collections
Imports System.IO
Imports System.Windows.Forms
Imports System.Drawing
Imports System.Drawing.Drawing2D

Public Class FileTextBox
    Inherits TextBox

#Region " Component Designer generated code "

    Public Sub New(ByVal Container As System.ComponentModel.IContainer)
        MyClass.New()

        'Required for Windows.Forms Class Composition Designer support
        Container.Add(Me)
    End Sub

    Public Sub New()
        MyBase.New()

        'This call is required by the Component Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Component 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 Component Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Component Designer
    'It can be modified using the Component Designer.
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        components = New System.ComponentModel.Container()
    End Sub

#End Region



    Protected Overrides Sub OnTextChanged(ByVal e As System.EventArgs)
        If Not File.Exists(Me.Text) Then
            Me.ForeColor = Color.Red
        Else
            Me.ForeColor = Color.Black
        End If

        MyBase.OnTextChanged(e)
    End Sub
End Class

14.23.TextBox
	14.23.1.	Get input from TextBox and Set to Label
	14.23.2.	Convert input value in a TextField
	14.23.3.	Inherit TextBox to create custom control based on TextBox
	14.23.4.	Display text file in a TextBox
	14.23.5.	Numeric TextBox
	14.23.6.	TextBox Text Changed Event
	14.23.7.	Comprehensive Demo for TextBox
	14.23.8.	Change TextBox font by RadioButton and CheckBox
	14.23.9.	Get selected text in TextBox
	14.23.10.	Create PasswordField by setting the TextBox.PasswordChar
	14.23.11.	Copy selection text from a TextBox and paste to another
	14.23.12.	Multiline Text Boxes
	14.23.13.	Disable TextBox Context Menu
	14.23.14.	Save text in TextBox to a file
	14.23.15.	Handles the Click event of a Button to change the background color of a TextBox.