VintaSoft Twain .NET SDK 15.2: 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 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