VintaSoft Twain .NET SDK 15.4: Documentation for .NET developer
In This Topic
Acquire images from eSCL scanner synchronously
In This Topic
VintaSoft Twain .NET SDK allows to acquire images from eSCL image scanner synchronously (in a modal loop).

Here are steps, which should be done for synchronous acquisition of images from eSCL device:
  1. Open eSCL device manager.
  2. Open eSCL device.
  3. Set the scanning settings.
  4. Start the synchronous acquisition of images from eSCL device by calling EsclDevice.AcquireImageSync or EsclDevice.AcquireImageSyncAsFileStream method.
  5. Break loop if EsclDevice.AcquireImageSync method returns null.

Here is an example that demonstrates how to synchronously acquire images from eSCL device and save acquired images to a PDF document:
/// <summary>
/// Synchronously acquire images from eSCL device.
/// </summary>
public void SynchronouslyAcquireImagesFromEsclDevice()
{
    // create eSCL device manager
    using (Vintasoft.EsclImageScanning.EsclDeviceManager deviceManager = new Vintasoft.EsclImageScanning.EsclDeviceManager())
    {
        // open eSCL device manager
        deviceManager.Open();

        // wait while the eSCL device manager searches for eSCL devices
        System.Threading.Thread.Sleep(deviceManager.DeviceSearchTimeout);
        // get count of eSCL devices
        int deviceCount = deviceManager.Devices.Count;
        if (deviceCount == 0)
        {
            System.Console.WriteLine("Devices are not found.");
            return;
        }

        // select the first eSCL device
        Vintasoft.EsclImageScanning.EsclDevice device = deviceManager.Devices[0];

        // open eSCL device
        device.Open();

        int imageIndex = 0;
        Vintasoft.EsclImageScanning.EsclAcquiredImage acquiredImage = null;
        do
        {
            try
            {
                // acquire image from eSCL device
                acquiredImage = device.AcquireImageSync();
                // if image is received
                if (acquiredImage != null)
                {
                    imageIndex++;
                    string filename = string.Format("scannedImage-{0}.png", imageIndex);
                    if (System.IO.File.Exists(filename))
                        System.IO.File.Delete(filename);

                    acquiredImage.Save(filename);

                    System.Console.WriteLine(string.Format("Acquired image is saved to a file '{0}'.", filename));
                }
                // if image is not received
                else
                {
                    System.Console.WriteLine("Scan is completed.");
                    break;
                }
            }
            catch (System.Exception ex)
            {
                System.Console.WriteLine(string.Format("Scan is failed: {0}", ex.Message));
                break;
            }
        }
        // while image is acquired
        while (acquiredImage != null);

        // close eSCL device
        device.Close();

        // close eSCL device manager
        deviceManager.Close();
    }

    System.Console.ReadLine();
}
''' <summary>
''' Synchronously acquire images from eSCL device.
''' </summary>
Public Sub SynchronouslyAcquireImagesFromEsclDevice()
    ' create eSCL device manager
    Using deviceManager As New Vintasoft.EsclImageScanning.EsclDeviceManager()
        ' open eSCL device manager
        deviceManager.Open()

        ' wait while the eSCL device manager searches for eSCL devices
        System.Threading.Thread.Sleep(deviceManager.DeviceSearchTimeout)
        ' get count of eSCL devices
        Dim deviceCount As Integer = deviceManager.Devices.Count
        If deviceCount = 0 Then
            System.Console.WriteLine("Devices are not found.")
            Return
        End If

        ' select the first eSCL device
        Dim device As Vintasoft.EsclImageScanning.EsclDevice = deviceManager.Devices(0)

        ' open eSCL device
        device.Open()

        Dim imageIndex As Integer = 0
        Dim acquiredImage As Vintasoft.EsclImageScanning.EsclAcquiredImage = Nothing
        Do
            Try
                ' acquire image from eSCL device
                acquiredImage = device.AcquireImageSync()
                ' if image is received
                If acquiredImage IsNot Nothing Then
                    imageIndex += 1
                    Dim filename As String = String.Format("scannedImage-{0}.png", imageIndex)
                    If System.IO.File.Exists(filename) Then
                        System.IO.File.Delete(filename)
                    End If

                    acquiredImage.Save(filename)

                    System.Console.WriteLine(String.Format("Acquired image is saved to a file '{0}'.", filename))
                Else
                    ' if image is not received
                    System.Console.WriteLine("Scan is completed.")
                    Exit Try
                End If
            Catch ex As System.Exception
                System.Console.WriteLine(String.Format("Scan is failed: {0}", ex.Message))
                Exit Try
            End Try
            ' while image is acquired
        Loop While acquiredImage IsNot Nothing

        ' close eSCL device
        device.Close()

        ' close eSCL device manager
        deviceManager.Close()
    End Using

    System.Console.ReadLine()
End Sub