[VB 2005] unire due file

8 Byte (un long) contenenti la dimensione del primo file (il jpg)
Tutto il primo file (jpg)
Tutto il secondo file

Private Sub TuoButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) _
        Handles TuoButton.Click
    JoinFiles("C:\spewer.exe", "C:\reflector.exe", "C:\joint")
    SplitFiles("C:\joint", "C:\a.exe", "C:\b.exe")
End Sub

Sub JoinFiles(ByVal jpg As String, ByVal txt As String, ByVal out As String)
    Using outwriter As New FileStream(out, FileMode.Create)
        Dim len As Long = New FileInfo(jpg).Length
        outwriter.Write(BitConverter.GetBytes(len), 0, 8)

        Dim buffer(10240) As Byte
        Dim read As Integer
        Using jpgread As New FileStream(jpg, FileMode.Open)
            Do
                read = jpgread.Read(buffer, 0, 10240)
                outwriter.Write(buffer, 0, read)
            Loop While read > 0
        End Using
        Using txtread As New FileStream(txt, FileMode.Open)
            Do
                read = txtread.Read(buffer, 0, 10240)
                outwriter.Write(buffer, 0, read)
            Loop While read > 0
        End Using
    End Using
End Sub

Sub SplitFiles(ByVal infile As String, ByVal jpg As String, ByVal txt As String)
    Using inreader As New FileStream(infile, FileMode.Open)
        Dim buffer(10240) As Byte
        inreader.Read(buffer, 0, 8)
        Dim len As Long = BitConverter.ToInt64(buffer, 0)
        Dim read As Integer

        Using jpgwriter As New FileStream(jpg, FileMode.Create)
            Dim left As Long = len
            While left > 0
                read = inreader.Read(buffer, 0, Math.Min(left, 10240))
                jpgwriter.Write(buffer, 0, read)
                left -= read
            End While
        End Using
        Using txtwriter As New FileStream(txt, FileMode.Create)
            Do
                read = inreader.Read(buffer, 0, 10240)
                txtwriter.Write(buffer, 0, read)
            Loop While read > 0
        End Using
    End Using
End Sub

Sub JoinFiles(ByVal jpg As String, ByVal txt As String, ByVal out As String)
    ' Crea il file che sarà l'unione dei due
    Using outstream As New FileStream(out, FileMode.Create)

        ' Ottiene le informazioni sui file jpg e txt
        Dim jpg_info As New FileInfo(jpg)
        Dim txt_info As New FileInfo(txt)

        ' Scrive la lunghezza del nome del jpg
        outstream.Write(BitConverter.GetBytes(jpg_info.Name.Length), 0, 4)
        ' Scrive la lunghezza del file jpg
        outstream.Write(BitConverter.GetBytes(jpg_info.Length), 0, 8)
        ' Scrive la lunghezza del nome del txt
        outstream.Write(BitConverter.GetBytes(txt_info.Name.Length), 0, 4)
        ' Scrive la lunghezza del file txt
        outstream.Write(BitConverter.GetBytes(txt_info.Length), 0, 8)

        ' Scrive il nome del file jpg
        outstream.Write(Encoding.UTF8.GetBytes(jpg_info.Name), 0, jpg_info.Name.Length)

        Dim buffer(10240) As Byte
        Dim read As Integer
        ' Scrive tutto il file jpg
        Using jpgread As New FileStream(jpg, FileMode.Open)
            Do
                read = jpgread.Read(buffer, 0, 10240)
                outstream.Write(buffer, 0, read)
            Loop While read > 0
        End Using

        ' Scrive il nome del file txt
        outstream.Write(Encoding.UTF8.GetBytes(txt_info.Name), 0, txt_info.Name.Length)

        ' Scrive tutto il file txt
        Using txtread As New FileStream(txt, FileMode.Open)
            Do
                read = txtread.Read(buffer, 0, 10240)
                outstream.Write(buffer, 0, read)
            Loop While read > 0
        End Using
    End Using
End Sub

Sub SplitFiles(ByVal infile As String)
    ' Apre il file da dividere per la lettura
    Using inreader As New FileStream(infile, FileMode.Open)

        Dim jpg_len, jpg_size, txt_len, txt_size As Integer

        Dim buffer(10240) As Byte
        Dim read As Integer

        ' Legge la lunghezza del nome del jpg, la dimensione del jpg,
        '       la lunghezza del nome del txt e la dimensione del txt
        read = inreader.Read(buffer, 0, 24)
        jpg_len = BitConverter.ToInt32(buffer, 0)
        jpg_size = BitConverter.ToInt64(buffer, 4)
        txt_len = BitConverter.ToInt32(buffer, 12)
        txt_size = BitConverter.ToUInt64(buffer, 16)

        ' Legge il nome del file jpg
        inreader.Read(buffer, 0, jpg_len)
        Dim jpg As String = Encoding.UTF8.GetString(buffer, 0, jpg_len)
        ' Estrae il file jpg
        Using jpgwriter As New FileStream(jpg, FileMode.Create)
            Dim left As Long = jpg_size
            While Left > 0
                read = inreader.Read(buffer, 0, Math.Min(Left, 10240))
                jpgwriter.Write(buffer, 0, read)
                left -= read
            End While
        End Using

        ' Legge il nome del file txt
        inreader.Read(buffer, 0, txt_len)
        Dim txt As String = Encoding.UTF8.GetString(buffer, 0, txt_len)
        ' Estrae il file txt
        Using txtwriter As New FileStream(txt, FileMode.Create)
            Dim left As Long = txt_size
            While left > 0
                read = inreader.Read(buffer, 0, 10240)
                txtwriter.Write(buffer, 0, read)
                left -= read
            End While
        End Using
    End Using
End Sub