Visual Basic

Public Class Test

    Public WithEvents BGW As System.ComponentModel.BackgroundWorker
    Private Test As Boolean

    Public Function FindAllMachines() As Boolean
        Test = False
        BGW = New System.ComponentModel.BackgroundWorker
        AddHandler BGW.DoWork, AddressOf BGW_DoWork
        AddHandler BGW.RunWorkerCompleted, AddressOf BGW_RunWorkerCompleted
        BGW.RunWorkerAsync()

        System.Threading.Thread.Sleep(30000)

        Return Test
    End Function

    Private Sub BGW_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs)
        e.Result = True
    End Sub

    Private Sub BGW_RunWorkerCompleted(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs)
        Test = True
    End Sub

End Class

Try

    'checking to make sure the text box isn't null'
    If (Decrypt_TextBox.Text = "") Then
        MessageBox.Show("Need to put in the file location or select file in grid for decryption")
    Else

        'declaring string for file'
        Dim filename As String
        'Getting the file name that is selected'

        filename = getFilename()
        'Starting to abstract the data from the database'
        database.ConnectionString = "Data Source = [name of database].db3;"
        database.Open()
        Dim command As SQLite.SQLiteCommand
        Dim sqlstatement As String
        command = database.CreateCommand
        'The following will get the bytes of the file'
        Dim filesize As Integer
        sqlstatement = "SELECT FileSize From [table name] WHERE FileName=@file;"
        command.CommandText = sqlstatement
        command.Parameters.AddWithValue("@file", filename)
        Dim reader As SQLite.SQLiteDataReader
        reader = command.ExecuteReader
        filesize = reader.GetValue(0)
        reader.Close()
        MessageBox.Show(filesize)
        Dim data(filesize) As Byte
        'The following should get the data'
        sqlstatement = "SELECT FileData FROM [table name] WHERE FileName=@file;"
        command.CommandText = sqlstatement
        command.Parameters.AddWithValue("@file", filename)

        Dim buf() As Byte


        'This gets the file from the database'
        reader = command.ExecuteReader


        'The following should get the file back to its original form'
        buf = reader.GetValue(0)
        MessageBox.Show(buf.Length)



        'This is go into the Safe and retrieve file'
        Dim datawrite As New System.IO.FileStream("filename", IO.FileMode.Open, IO.FileAccess.ReadWrite)
        datawrite.SetLength(0)
        datawrite.Write(buf, 0, buf.Length)
        datawrite.Close()
        reader.Close()
        Dim fileinput As New System.IO.FileStream("filename", IO.FileMode.Open, IO.FileAccess.ReadWrite)

        'specific file output location wiht proper extension'
        Dim fileoutput As New System.IO.FileStream(Decrypt_TextBox.Text & "\" & filename, IO.FileMode.OpenOrCreate, IO.FileAccess.Write)
        'The next line makes sure that the file is empty'

        'Declaring variables for encryption'

        Dim buffer(4096) As Byte 'Holds the bytes for processing

        Dim BytesProcessed As Double 'running count for bytes that are processed'

        Dim filelength As Double = fileinput.Length() 'Length of file coming in where intEnd will be greater than intStart'

        Dim bytesinblock As Integer 'current bytes in block'

        Dim crypto As CryptoStream

        'Declaring crypto service provider'
        Dim scRijndael As New System.Security.Cryptography.RijndaelManaged

        'setting up progress bars
        Encrypt_ProgressBar.Value = 0
        Encrypt_ProgressBar.Maximum = 100

        crypto = New CryptoStream(fileoutput, scRijndael.CreateDecryptor(key, IV), CryptoStreamMode.Write)

        While BytesProcessed < filelength
            'reading the file'
            bytesinblock = fileinput.Read(buffer, 0, 4096)
            'writing the file to cryptoStream'
            crypto.Write(buffer, 0, bytesinblock)
            'updating bytes processed'
            BytesProcessed = BytesProcessed + CLng(bytesinblock)
            'equation for updating bytes in block'
            Decrypt_ProgressBar.Value = CInt((BytesProcessed / filelength) * 100)
        End While

        crypto.Close()

        fileoutput.Close()
        fileinput.Close()

        MessageBox.Show("File is done decrypting")
        Decrypt_ProgressBar.Step = 0
        Decrypt_ProgressBar.Value = 0
        Decrypt_TextBox.Text = ""
    End If

Catch ex As Exception
    MsgBox(ex.Message.ToString)


End Try

Return 1