Display text file in a TextBox : TextBox « GUI « VB.Net Tutorial






Display text file in a TextBox
Imports System.IO

Imports System.Windows.Forms

public class TextFileDisplayTextBox
   public Shared Sub Main
        Application.Run(New 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.ComponentModel.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, 24)
        Me.Button1.Name = "Button1"
        Me.Button1.TabIndex = 0
        Me.Button1.Text = "Select a File"
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(20, 80)
        Me.TextBox1.Multiline = True
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(250, 150)
        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.AddRange(New System.Windows.Forms.Control() {Me.Button1, Me.TextBox1})
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim FileDB As New OpenFileDialog()

        FileDB.Filter = "All files | *.* | Word files | *.doc | Text files | *.txt"

        FileDB.FilterIndex = 3

        FileDB.InitialDirectory = "C:\Temp"

        If (FileDB.ShowDialog() = DialogResult.OK) Then
            Dim FS As FileStream

            Try
                FS = FileDB.OpenFile()
            Catch
                MsgBox("Error opening " & FileDB.FileName)
            End Try

            Dim TextData(1025) As Byte
            Dim BytesRead As Integer
            Dim I As Integer
            Dim NewText As String

            Do
                Try
                    BytesRead = FS.Read(TextData, 1, 1024)

                    NewText = ""
                    For I = 1 To BytesRead
                        NewText = NewText & Chr(TextData(I))
                    Next
                    TextBox1.AppendText(NewText)
                Catch
                    MsgBox("Error reading file")
                End Try

            Loop While (BytesRead <> 0)

            FS.Close()
        Else
                MsgBox("User selected Cancel")
        End If

    End Sub
End Class








14.23.TextBox
14.23.1.Get input from TextBox and Set to LabelGet input from TextBox and Set to Label
14.23.2.Convert input value in a TextFieldConvert 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 TextBoxDisplay text file in a TextBox
14.23.5.Numeric TextBoxNumeric TextBox
14.23.6.TextBox Text Changed EventTextBox Text Changed Event
14.23.7.Comprehensive Demo for TextBoxComprehensive Demo for TextBox
14.23.8.Change TextBox font by RadioButton and CheckBoxChange TextBox font by RadioButton and CheckBox
14.23.9.Get selected text in TextBoxGet selected text in TextBox
14.23.10.Create PasswordField by setting the TextBox.PasswordCharCreate PasswordField by setting the TextBox.PasswordChar
14.23.11.Copy selection text from a TextBox and paste to anotherCopy selection text from a TextBox and paste to another
14.23.12.Multiline Text BoxesMultiline Text Boxes
14.23.13.Disable TextBox Context MenuDisable 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.