Private _ftpUpload As Vintasoft.Twain.ImageUploading.Ftp.FtpUpload = Nothing

Private _isDataSending As Boolean


''' <summary>
''' Uploads TWAIN acquired image to FTP server.
''' </summary>
Public Sub UploadTwainAcquiredImageToFtpServer(acquiredImage As Vintasoft.Twain.AcquiredImage)
    Try
        _isDataSending = False

        ' create FTP uploader
        _ftpUpload = New Vintasoft.Twain.ImageUploading.Ftp.FtpUpload()

        ' subscribe to the events
        AddHandler _ftpUpload.StatusChanged, New System.EventHandler(Of Vintasoft.Twain.ImageUploading.Ftp.StatusChangedEventArgs)(AddressOf _ftpUpload_StatusChanged)
        AddHandler _ftpUpload.ProgressChanged, New System.EventHandler(Of Vintasoft.Twain.ImageUploading.Ftp.ProgressChangedEventArgs)(AddressOf _ftpUpload_ProgressChanged)
        AddHandler _ftpUpload.Completed, New System.EventHandler(Of Vintasoft.Twain.ImageUploading.Ftp.CompletedEventArgs)(AddressOf _ftpUpload_Completed)

        ' set FTP upload parameters
        _ftpUpload.Host = "ftp.test.com"
        _ftpUpload.User = "user"
        _ftpUpload.Password = "password"
        _ftpUpload.PassiveMode = True
        _ftpUpload.Timeout = 2000
        _ftpUpload.Path = "/images/"
        _ftpUpload.AddFile("scan.jpg", acquiredImage.GetAsStream(New Vintasoft.Twain.ImageEncoders.TwainJpegEncoderSettings()))

        ' post data to the server
        _ftpUpload.PostData()
    Catch ex As System.Exception
        System.Console.WriteLine(ex.Message)
    End Try
End Sub

''' <summary>
''' Status of FTP uploading is changed.
''' </summary>
Private Sub _ftpUpload_StatusChanged(sender As Object, e As Vintasoft.Twain.ImageUploading.Ftp.StatusChangedEventArgs)
    ' show current upload status in the status string
    System.Console.WriteLine(e.StatusString)
End Sub

''' <summary>
''' FTP uploading is in progress.
''' </summary>
Private Sub _ftpUpload_ProgressChanged(sender As Object, e As Vintasoft.Twain.ImageUploading.Ftp.ProgressChangedEventArgs)
    ' show the size of uploading data (once per upload)
    If Not _isDataSending Then
        System.Console.WriteLine(String.Format("Total bytes: {0}", e.BytesTotal))
        _isDataSending = True
    End If

    ' show current upload progress, in bytes, in the status string
    System.Console.WriteLine(String.Format("Bytes uploaded: {0}", e.BytesUploaded))
End Sub

''' <summary>
''' FTP uploading is completed.
''' </summary>
Private Sub _ftpUpload_Completed(sender As Object, e As Vintasoft.Twain.ImageUploading.Ftp.CompletedEventArgs)
    If e.ErrorCode = Vintasoft.Twain.ImageUploading.Ftp.ErrorCode.None Then
        System.Console.WriteLine("FTP: Image is uploaded successfully!")
    Else
        System.Console.WriteLine(String.Format("FTP error: {0}", e.ErrorString))
    End If
End Sub

Vintasoft.Twain.ImageUploading.Ftp.FtpUpload _ftpUpload = null;

bool _isDataSending;


/// <summary>
/// Uploads TWAIN acquired image to FTP server.
/// </summary>
public void UploadTwainAcquiredImageToFtpServer(Vintasoft.Twain.AcquiredImage acquiredImage)
{
    try
    {
        _isDataSending = false;

        // create FTP uploader
        _ftpUpload = new Vintasoft.Twain.ImageUploading.Ftp.FtpUpload();

        // subscribe to the events
        _ftpUpload.StatusChanged += new System.EventHandler<Vintasoft.Twain.ImageUploading.Ftp.StatusChangedEventArgs>(_ftpUpload_StatusChanged);
        _ftpUpload.ProgressChanged += new System.EventHandler<Vintasoft.Twain.ImageUploading.Ftp.ProgressChangedEventArgs>(_ftpUpload_ProgressChanged);
        _ftpUpload.Completed += new System.EventHandler<Vintasoft.Twain.ImageUploading.Ftp.CompletedEventArgs>(_ftpUpload_Completed);

        // set FTP upload parameters
        _ftpUpload.Host = "ftp.test.com";
        _ftpUpload.User = "user";
        _ftpUpload.Password = "password";
        _ftpUpload.PassiveMode = true;
        _ftpUpload.Timeout = 2000;
        _ftpUpload.Path = "/images/";
        _ftpUpload.AddFile("scan.jpg", acquiredImage.GetAsStream(new Vintasoft.Twain.ImageEncoders.TwainJpegEncoderSettings()));

        // post data to the server
        _ftpUpload.PostData();
    }
    catch (System.Exception ex)
    {
        System.Console.WriteLine(ex.Message);
    }
}

/// <summary>
/// Status of FTP uploading is changed.
/// </summary>
private void _ftpUpload_StatusChanged(object sender, Vintasoft.Twain.ImageUploading.Ftp.StatusChangedEventArgs e)
{
    // show current upload status in the status string
    System.Console.WriteLine(e.StatusString);
}

/// <summary>
/// FTP uploading is in progress.
/// </summary>
private void _ftpUpload_ProgressChanged(object sender, Vintasoft.Twain.ImageUploading.Ftp.ProgressChangedEventArgs e)
{
    // show the size of uploading data (once per upload)
    if (!_isDataSending)
    {
        System.Console.WriteLine(string.Format("Total bytes: {0}", e.BytesTotal));
        _isDataSending = true;
    }

    // show current upload progress, in bytes, in the status string
    System.Console.WriteLine(string.Format("Bytes uploaded: {0}", e.BytesUploaded));
}

/// <summary>
/// FTP uploading is completed.
/// </summary>
private void _ftpUpload_Completed(object sender, Vintasoft.Twain.ImageUploading.Ftp.CompletedEventArgs e)
{
    if (e.ErrorCode == Vintasoft.Twain.ImageUploading.Ftp.ErrorCode.None)
        System.Console.WriteLine("FTP: Image is uploaded successfully!");
    else
        System.Console.WriteLine(string.Format("FTP error: {0}", e.ErrorString));
}