Remove blank lines at the end of a file - vb.net

Question

I am trying to remove the blank lines at the end of a text file. The program takes a file, manipulates it and produces another file. However, there's blank lines at the end of the file that I need to get rid of...
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
' Save to desktop if nothing is selected
If txtDestLoc.Text = "" Then
txtDestLoc.Text = "C:\Documents and Settings\" & LCase(Environment.UserName) & "\desktop"
End If
If txtFileLoc.Text <> "" Then
Dim fsr As New FileStream(txtFileLoc.Text, FileMode.Open)
Dim sr As New StreamReader(fsr)
Dim sb As New System.Text.StringBuilder
'Dim strHeader As String
' Get just file name
Dim strFileName = Me.OpenFileDialog1.FileName()
Dim fnPeices() As String = strFileName.Split("\")
Dim fileName As String = ""
fileName = "CCCPositivePay.txt"
Dim strOutFile As String = txtDestLoc.Text & "\" & fileName
Dim fsw As New FileStream(strOutFile, FileMode.Create, FileAccess.Write)
Dim w As New StreamWriter(fsw)
Dim i As Double
Dim srRow As String
Dim strW As String
Dim strDate As String
Dim strAmt As String
Dim strChNo As String
Dim strName As String
Dim strAddInfo As String
Dim strCustAcct As String
Dim totamt As Double = 0
Dim strAcct As String = "2000002297330"
strLoc = txtDestLoc.Text()
srRow = ""
Do While sr.Peek() <> -1
srRow = srRow.ToString & sr.ReadLine()
If srRow.Length = 133 Then
If srRow.Substring(131, 2) = "CR" Then
strCustAcct = srRow.Substring(2, 18).Replace("-", "")
strName = srRow.Substring(23, 35)
strAddInfo = srRow.Substring(23, 30)
strDate = srRow.Substring(103, 4) + srRow.Substring(97, 2) + srRow.Substring(100, 2)
strChNo = srRow.Substring(110, 10)
strAmt = strip(srRow.Substring(121, 10))
strW = strAcct + strChNo.Trim.PadLeft(10, "0") + strAmt.Trim.PadLeft(10, "0") + strDate + " " + strAddInfo + Space(8) + strName + Space(20)
sb.AppendLine(strW)
totamt = totamt + CDbl(strAmt)
i = i + 1
End If
End If
srRow = ("")
Loop
'w.WriteLine(strHeader)
w.WriteLine(sb.ToString)
Dim file As String = txtFileLoc.Text
Dim path As String = txtFileLoc.Text.Substring(0, File.lastindexof("\"))
Dim strFileProcessed As String
strFileProcessed = fnPeices(fnPeices.Length - 1)
Label1.Text = "Refund File Processed: " & strFileProcessed
Label2.Text = "File saved to: " & strOutFile
' Close everything
w.Close()
sr.Close()
fsw.Close()
fsr.Close()
' Move file after processing
System.IO.File.Move(file, path + "\CB008_Processed\" + Now.ToString("MMddyyyyHHmm") + strFileProcessed)
' Put a copy of the results in "Processed" folder
System.IO.File.Copy(strOutFile, path + "\CB008_Processed\" + Now.ToString("MMddyyyyHHmm") + fileName)
Else
MessageBox.Show("Please select a Refund file to process.", "CCC Refund File", MessageBoxButtons.OK)
End If
End Sub
Public Function strip(ByVal des As String)
Dim strorigFileName As String
Dim intCounter As Integer
Dim arrSpecialChar() As String = {".", ",", "<", ">", ":", "?", """", "/", "{", "[", "}", "]", "`", "~", "!", "#", "#", "$", "%", "^", "&", "*", "(", ")", "_", "-", "+", "=", "|", " ", "\"}
strorigFileName = des
intCounter = 0
Dim i As Integer
For i = 0 To arrSpecialChar.Length - 1
Do Until intCounter = 29
des = Replace(strorigFileName, arrSpecialChar(i), "")
intCounter = intCounter + 1
strorigFileName = des
Loop
intCounter = 0
Next
Return strorigFileName
End Function

Answer 1

Only do a Writeline if Not String.IsNullOrEmpty(sb)