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 is to do list for acquiring images synchronously:

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

Here is an example that demonstrates how to acquire images in modal loop using TWAIN scanner driver user interface and save acquired images into PDF document:

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();
        }

    }
}

VB.NET

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

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