namespace TwainExamples_CSharp
{
    class SyncScan
    {

        /// <summary>
        /// Acquire images synchronously.
        /// </summary>
        public void AcquireImagesSynchronously()
        {
            try
            {
                using (Vintasoft.Twain.DeviceManager deviceManager = new Vintasoft.Twain.DeviceManager())
                {
                    // open the device manager
                    deviceManager.Open();

                    // get reference to the default device
                    Vintasoft.Twain.Device device = deviceManager.DefaultDevice;

                    // open the device
                    device.Open();

                    // set acquisition parameters
                    device.TransferMode = Vintasoft.Twain.TransferMode.Memory;
                    device.ShowUI = false;
                    device.DisableAfterAcquire = true;
                    device.PixelType = Vintasoft.Twain.PixelType.BW;

                    // create directory for PDF document
                    string directoryForImages = System.IO.Path.GetDirectoryName(System.IO.Directory.GetCurrentDirectory());
                    directoryForImages = System.IO.Path.Combine(directoryForImages, "Images");
                    if (!System.IO.Directory.Exists(directoryForImages))
                        System.IO.Directory.CreateDirectory(directoryForImages);

                    string pdfFilename = System.IO.Path.Combine(directoryForImages, "multipage.pdf");

                    // acquire image(s) from the device
                    Vintasoft.Twain.AcquireModalState acquireModalState = Vintasoft.Twain.AcquireModalState.None;
                    int imageIndex = 0;
                    do
                    {
                        acquireModalState = device.AcquireModal();
                        switch (acquireModalState)
                        {
                            case Vintasoft.Twain.AcquireModalState.ImageAcquired:
                                // save image to file
                                device.AcquiredImage.Save(pdfFilename);
                                // dispose acquired image
                                device.AcquiredImage.Dispose();
                                // output current state
                                System.Console.WriteLine(string.Format("Image{0} is saved.", imageIndex++));
                                break;

                            case Vintasoft.Twain.AcquireModalState.ScanCompleted:
                                // output current state
                                System.Console.WriteLine("Scan completed.");
                                break;

                            case Vintasoft.Twain.AcquireModalState.ScanCanceled:
                                // output current state
                                System.Console.WriteLine("Scan canceled.");
                                break;

                            case Vintasoft.Twain.AcquireModalState.ScanFailed:
                                // output current state
                                System.Console.WriteLine(string.Format("Scan failed: {0}", device.ErrorString));
                                break;
                        }
                    }
                    while (acquireModalState != Vintasoft.Twain.AcquireModalState.None);

                    // close the device
                    device.Close();

                    // close the device manager
                    deviceManager.Close();
                }
            }
            catch (Vintasoft.Twain.TwainException ex)
            {
                System.Console.WriteLine("Error: " + ex.Message);
            }

            System.Console.ReadLine();
        }

    }
}

Class SyncScan

    ''' <summary>
    ''' Acquire images synchronously.
    ''' </summary>
    Public Sub AcquireImagesSynchronously()
        Try
            Using deviceManager As New Vintasoft.Twain.DeviceManager()
                ' open the device manager
                deviceManager.Open()

                ' get reference to the default device
                Dim device As Vintasoft.Twain.Device = deviceManager.DefaultDevice

                ' open the device
                device.Open()

                ' set acquisition parameters
                device.TransferMode = Vintasoft.Twain.TransferMode.Memory
                device.ShowUI = False
                device.DisableAfterAcquire = True
                device.PixelType = Vintasoft.Twain.PixelType.BW

                ' create directory for PDF document
                Dim directoryForImages As String = IO.Path.GetDirectoryName(IO.Directory.GetCurrentDirectory())
                directoryForImages = IO.Path.Combine(directoryForImages, "Images")
                If Not IO.Directory.Exists(directoryForImages) Then
                    IO.Directory.CreateDirectory(directoryForImages)
                End If

                Dim pdfFilename As String = IO.Path.Combine(directoryForImages, "multipage.pdf")

                ' acquire image(s) from the device
                Dim acquireModalState1 As Vintasoft.Twain.AcquireModalState = Vintasoft.Twain.AcquireModalState.None
                Dim imageIndex As Integer = 0
                Do
                    acquireModalState1 = device.AcquireModal()
                    Select Case acquireModalState1
                        Case Vintasoft.Twain.AcquireModalState.ImageAcquired
                            ' save image to file
                            device.AcquiredImage.Save(pdfFilename)
                            ' dispose acquired image
                            device.AcquiredImage.Dispose()
                            ' output current state
                            Console.WriteLine(String.Format("Image{0} is saved.", System.Math.Max(System.Threading.Interlocked.Increment(imageIndex), imageIndex - 1)))
                            Exit Select

                        Case Vintasoft.Twain.AcquireModalState.ScanCompleted
                            ' output current state
                            Console.WriteLine("Scan completed.")
                            Exit Select

                        Case Vintasoft.Twain.AcquireModalState.ScanCanceled
                            ' output current state
                            Console.WriteLine("Scan canceled.")
                            Exit Select

                        Case Vintasoft.Twain.AcquireModalState.ScanFailed
                            ' output current state
                            Console.WriteLine(String.Format("Scan failed: {0}", device.ErrorString))
                            Exit Select
                    End Select
                Loop While acquireModalState1 <> Vintasoft.Twain.AcquireModalState.None

                ' close the device
                device.Close()

                ' close the device manager
                deviceManager.Close()
            End Using
        Catch ex As Vintasoft.Twain.TwainException
            Console.WriteLine("Error: " + ex.Message)
        End Try

        Console.ReadLine()
    End Sub

End Class