VB2008 Changing string in a file - vb.net

Question

I want to change something on a compiled game file, so I used this code:
Private Sub Next2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Next2.Click
Dim reader As New System.IO.StreamReader("Languages/" & Language & ".Devil")
Dim allLines As List(Of String) = New List(Of String)
Do While Not reader.EndOfStream
allLines.Add(reader.ReadLine())
Loop
reader.Close()
Tips.Text = ReadLine(6, allLines)
WeaponsListBox.Hide()
NewWeaponsList.Hide()
Next2.Hide()
Dim curItem As String = WeaponsListBox.SelectedItem.ToString()
Dim curItem2 As String = NewWeaponsList.SelectedItem.ToString()
Try
If MainWeapon = "Cheytac" Then
Dim supahotfire As String = curItem.Substring(0, 12)
Dim hotdestroyer As String = curItem.Replace(supahotfire, "")
Dim supa2 As String = curItem2.Substring(0, 12)
Dim hot2 As String = curItem2.Replace(supa2, "")
Dim oldfile As String = "pack/Weapon_" & curItem & ".i3pack"
Dim FileName As String = "pack/pack_" & MainWeapon & hot2 & "_" & hotdestroyer & ".i3pack"
Dim be = My.Computer.FileSystem.ReadAllBytes(oldfile)
Dim be2 As String = UnicodeBytesToString(be)
be2.Replace("Weapon\" & curItem & "/" & curItem & "_diff", "Weapon\" & curItem2 & "/" & curItem2 & "_diff")
Dim be3 As String = be2.Replace("Weapon\" & curItem & "/Cheytac_M200_Diff.i3i", "Weapon\" & curItem2 & "/Cheytac_M200_Diff.i3i")
Dim be4 = UnicodeStringToBytes(be3)
My.Computer.FileSystem.WriteAllBytes(FileName, be4, True)
'System.IO.File.AppendAllText(FileName, be4)
' Dim fs As FileStream = New FileStream(oldfile, FileMode.Open)
' Dim br As BinaryReader = New BinaryReader(fs)
'Dim bin as byte[]= br.ReadBytes(Convert.ToInt32(fs.Length));
' fs.Close()
'br.Close()
End If
Catch ex As Exception
System.IO.File.AppendAllText("MathimaticalErrors.txt", ex.ToString)
End Try
End Sub
Public Function UnicodeBytesToString(ByVal bytes() As Byte) As String
Return System.Text.Encoding.Unicode.GetString(bytes)
End Function
Public Function UnicodeStringToBytes(ByVal str As String) As Byte()
Return System.Text.Encoding.Unicode.GetBytes(str)
End Function
The problem is that the newly created file is basically the same as the old file, and nothing has changed on it. How can I solve this?

Answer 1

At this point in your code:
Dim be2 As String = UnicodeBytesToString(be)
be2.Replace("Weapon\" & curItem & "/" & curItem & "_diff", "Weapon\" & curItem2 & "/" & curItem2 & "_diff")
The value in be2 would remain unchanged. You have to store the return value of Replace():
Dim be2 As String = UnicodeBytesToString(be)
be2 = be2.Replace("Weapon\" & curItem & "/" & curItem & "_diff", "Weapon\" & curItem2 & "/" & curItem2 & "_diff")
Also, at this line:
My.Computer.FileSystem.WriteAllBytes(FileName, be4, True)
The True at the end means you want to append the bytes. If the file is empty this will be fine. If not, then you'll end up adding the bytes to the end of the file each time. Not sure if that is your intended result...