Read Text File and Output Multiple Lines to a Textbox - vb.net

Question

I'm trying to read a text file with multiple lines and then display it in a textbox. The problem is that my program only reads one line. Can someone point out the mistake to me?
Imports System.IO
Imports Microsoft.VisualBasic.FileIO
Public Class Form1
Private BagelStreamReader As StreamReader
Private PhoneStreamWriter As StreamWriter
Dim ResponseDialogResult As DialogResult
Private Sub OpenToolStripMenuItem_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles OpenToolStripMenuItem.Click
'Dim PhoneStreamWriter As New StreamWriter(OpenFileDialog1.FileName)
'Is file already open
If PhoneStreamWriter IsNot Nothing Then
PhoneStreamWriter.Close()
End If
With OpenFileDialog1
.InitialDirectory = Directory.GetCurrentDirectory
.FileName = OpenFileDialog1.FileName
.Title = "Select File"
ResponseDialogResult = .ShowDialog()
End With
'If ResponseDialogResult <> DialogResult.Cancel Then
' PhoneStreamWriter = New StreamWriter(OpenFileDialog1.FileName)
'End If
Try
BagelStreamReader = New StreamReader(OpenFileDialog1.FileName)
DisplayRecord()
Catch ex As Exception
MessageBox.Show("File not found or is invalid.", "Data Error")
End Try
End Sub
Private Sub DisplayRecord()
Do Until BagelStreamReader.Peek = -1
TextBox1.Text = BagelStreamReader.ReadLine()
Loop
'MessageBox.Show("No more records to display.", "End of File")
'End If
End Sub
Private Sub SaveToolStripMenuItem_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles SaveToolStripMenuItem.Click
With SaveFileDialog1
.InitialDirectory = Directory.GetCurrentDirectory
.FileName = OpenFileDialog1.FileName
.Title = "Select File"
ResponseDialogResult = .ShowDialog()
End With
PhoneStreamWriter.WriteLine(TextBox1.Text)
With TextBox1
.Clear()
.Focus()
End With
TextBox1.Clear()
End Sub
Private Sub ExitToolStripMenuItem_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles ExitToolStripMenuItem.Click
Dim PhoneStreamWriter As New StreamWriter(OpenFileDialog1.FileName)
PhoneStreamWriter.Close()
Me.Close()
End Sub
End Class
Here is a sample textfile:
Banana nut
Blueberry
Cinnamon
Egg
Plain
Poppy Seed
Pumpkin
Rye
Salt
Sesame seed

Answer 1

You're probably only getting the last line in the file, right? Your code sets TextBox1.Text equal to BagelSteramReader.ReadLine() every time, overwriting the previous value of TextBox1.Text. Try TextBox1.Text += BagelStreamReader.ReadLine() + '\n'
Edit: Though I must steal agree with Hans Passant's commented idea on this; If you want an more efficient algorithm, File.ReadAllLines() even saves you time and money...though I didn't know of it myself. Darn .NET, having so many features...

Answer 2

I wrote a program to both write to and read from a text file. To write the lines of a list box to a text file I used the following code:
Private Sub txtWriteToTextfile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtWriteToTextfile.Click
Dim FileWriter As StreamWriter
FileWriter = New StreamWriter(FileName, False)
' 3. Write some sample data to the file.
For i = 1 To lstNamesList.Items.Count
FileWriter.Write(lstNamesList.Items(i - 1).ToString)
FileWriter.Write(Chr(32))
Next i
FileWriter.Close()
End Sub
And to read and write the contents of the text file and write to a multi-line text box (you just need to set the multiple lines property of a text box to true) I used the following code. I also had to do some extra coding to break the individual words from the long string I received from the text file.
Private Sub cmdReadFromTextfile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdReadFromTextfile.Click
Dim sStringFromFile As String = ""
Dim sTextString As String = ""
Dim iWordStartingPossition As Integer = 0
Dim iWordEndingPossition As Integer = 0
Dim iClearedTestLength As Integer = 0
Dim FileReader As StreamReader
FileReader = New StreamReader(FileName)
sStringFromFile = FileReader.ReadToEnd()
sTextString = sStringFromFile
txtTextFromFile.Text = ""
Do Until iClearedTestLength = Len(sTextString)
iWordEndingPossition = CInt(InStr((Microsoft.VisualBasic.Right(sTextString, Len(sTextString) - iWordStartingPossition)), " "))
txtTextFromFile.Text = txtTextFromFile.Text & (Microsoft.VisualBasic.Mid(sTextString, iWordStartingPossition + 1, iWordEndingPossition)) & vbCrLf
iWordStartingPossition = iWordStartingPossition + iWordEndingPossition
iClearedTestLength = iClearedTestLength + iWordEndingPossition
Loop
FileReader.Close()
End Sub