Acquire images from TWAIN scanner synchronously

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VintaSoft Twain .NET SDK allows to acquire images from TWAIN 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 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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