Acquire images from TWAIN image scanner synchronously

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VintaSoft Twain .NET SDK allows to acquire images from TWAIN image scanner synchronously (in a modal loop).

Here are steps, which should be made for synchronous acquisition of images from TWAIN device:

Open TWAIN device manager.
Select TWAIN device.
Open TWAIN device.
Set the TWAIN device settings.
Start the synchronous acquisition of images from TWAIN device by calling Device.AcquireModal method.
Retrieve acquired images one by one while Device.AcquireModal method returns AcquireModalState.ImageAcquired.
Break loop if Device.AcquireModal method returns AcquireModalState.None.

Here is an example that demonstrates how to synchronously acquire images from TWAIN image scanner and save acquired images to a PDF document:

/// <summary>
/// Synchronously acquire images from TWAIN device.
/// </summary>
public void SynchronouslyAcquireImagesFromTwainDevice()
{
    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();
}

VB.NET

''' <summary>
''' Synchronously acquire images from TWAIN device.
''' </summary>
Public Sub SynchronouslyAcquireImagesFromTwainDevice()
    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 = System.IO.Path.GetDirectoryName(System.IO.Directory.GetCurrentDirectory())
            directoryForImages = System.IO.Path.Combine(directoryForImages, "Images")
            If Not System.IO.Directory.Exists(directoryForImages) Then
                System.IO.Directory.CreateDirectory(directoryForImages)
            End If

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

            ' acquire image(s) from the device
            Dim acquireModalState As Vintasoft.Twain.AcquireModalState = Vintasoft.Twain.AcquireModalState.None
            Dim imageIndex As Integer = 0
            Do
                acquireModalState = device.AcquireModal()
                Select Case 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.", System.Math.Max(System.Threading.Interlocked.Increment(imageIndex), imageIndex - 1)))
                        Exit Select

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

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

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

            ' close the device
            device.Close()

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

    System.Console.ReadLine()
End Sub

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