Android Question how to Resume file transfer using AsyncStreams

       Private Sub sendFile(fileToSend As String, Targetfilepath As String, Client As Socket)
            Try
                Dim adler As New Adler32()

                Using fs As New FileStream(fileToSend, FileMode.Open, FileAccess.Read, FileShare.Read)
                    Dim name As Byte() = Encoding.UTF8.GetBytes((Targetfilepath))
                    Dim Stream = New NetworkStream(Client)
                    Dim bw As New BinaryWriter(Stream)
                    'send the first message which is the file name
                    bw.Write(name.Length)
                    bw.Write(name)
                    'send the stream message
                    bw.Write(STREAM_PREFIX)
                    Dim size As Long = New FileInfo(fileToSend).Length
                    bw.Write(size) 'Send the total file length
                    Dim written As Long = 0
                    Dim buffer As Byte() = New Byte(BufferSize) {}
                    While written < size
                        Dim count As Integer = fs.Read(buffer, 0, Math.Min(CLng(size - written), buffer.Length))
                        Stream.Write(buffer, 0, count)
                        adler.Update(buffer, 0, count)
                        written += count
                    End While
                    bw.Write(adler.Value)
                    'log("File sent successfully.")
                End Using
            Catch e As Exception
                'mDelRemoveDisconnected()


            End Try
            'Dim mi As MethodInvoker = Sub() btnSend.Enabled = Not btnConnect.Enabled
            'Me.BeginInvoke(mi)
        End Sub

    Dim bc As ByteConverter
    bc.LittleEndian=True
    Dim Buffer (65535) As Byte, Read As Int
    Try
    Dim inStream As InputStream=client.InputStream
    Dim count As Int
       
    Dim LengthBytes(4) As Byte,Length As Int
    count=inStream.ReadBytes (LengthBytes,0,4)
    If count=-1 Then Return True
   
   
    Length =bc.IntsFromBytes(LengthBytes)(0)
   
   
    Dim TypeB(1) As Byte
    inStream.ReadBytes (TypeB,0,1)

    Select Case TypeB(0)
        Case 67'Command
            Dim CommandBytes(Length-1) As Byte
            inStream.ReadBytes (CommandBytes,0,Length-1)
           
            Dim nCommandData As String=BytesToString(CommandBytes , 0, Length-1,"utf8")
            ProcessCommand(nCommandData)
       
        Case 70'File
            '------------- Read FileName -------------
            Dim FileNameBytes(Length-1) As Byte
            inStream.ReadBytes (FileNameBytes,0,Length-1)
            currentFile= BytesToString(FileNameBytes , 0, Length-1,"utf8")
            '-----------------------------------------
           
            '------------ Read File Length as long 8 bytes
            Dim FileLengthBytes(8) As Byte
            inStream.ReadBytes (FileLengthBytes,0,8)
           
            Dim FileLength As Long =bc.LongsFromBytes(FileLengthBytes)(0)
           
            Dim outFile As OutputStream = File.OpenOutput(MainHelper.ActiveOfflineDirectory, currentFile, True)
           
            '------------ Read File Data -------------
            '-------- Write File Data
           
            Do While Read < FileLength
               
                count=inStream.ReadBytes(Buffer,0,Min((FileLength-Read),Buffer.Length ))
                   
                'Write To File

   
                outFile.WriteBytes(Buffer, 0, count)

                'Increment CRC32
                progressValue = 100 * Read / FileLength
                UpdateProgress(False)
                Read=Read+count
                DoEvents
            Loop
           
            Dim ChecksumBytes (8) As Byte
            inStream.ReadBytes(ChecksumBytes,0,8)
            outFile.Close
           
           
        End Select
    Catch
        Log(LastException)
        ConnectSocket
    End Try


      Return False

Dim CommandBytes(Length-1) As Byte
            inStream.ReadBytes (CommandBytes,0,Length-1)
          
            Dim nCommandData As String=BytesToString(CommandBytes , 0, Length-1,"utf8")
            ProcessCommand(nCommandData)