VintaSoft Twain .NET SDK 15.4: Documentation for .NET developer
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Cancel image acquisition from SANE image scanner
In This Topic
You should call the SaneLocalDevice.CancelImageTransfer method if you want to cancel the image acquisition from SANE image scanner.

Here is an example that demonstrates how to cancel the current synchronous image transfer from SANE image scanner:
/// <summary>
/// Acquires one image from SANE device and cancels image transfer.
/// </summary>
public static void AcquireOneImageFromSaneDeviceAndCancelScan()
{
    // create SANE device manager
    using (Vintasoft.Sane.SaneLocalDeviceManager deviceManager = new Vintasoft.Sane.SaneLocalDeviceManager())
    {
        // open SANE device manager
        deviceManager.Open();

        // get count of SANE devices
        int deviceCount = deviceManager.Devices.Count;
        if (deviceCount == 0)
        {
            System.Console.WriteLine("Devices are not found.");
            return;
        }

        // select the first SANE device
        Vintasoft.Sane.SaneLocalDevice device = deviceManager.Devices[0];

        // open SANE device
        device.Open();

        Vintasoft.Sane.SaneAcquiredImage acquiredImage;
        do
        {
            try
            {
                // acquire image from SANE device
                acquiredImage = device.AcquireImageSync();
                // if image is received
                if (acquiredImage != null)
                {
                    System.Console.WriteLine("Image is acquired.");

                    // cancel image transfer
                    device.CancelImageTransfer();
                }
                // 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 device has more images to scan
        while (device.HasMoreImagesToScan);

        // close SANE device
        device.Close();

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

    System.Console.ReadLine();
}
''' <summary>
''' Acquires one image from SANE device and cancels image transfer.
''' </summary>
Public Shared Sub AcquireOneImageFromSaneDeviceAndCancelScan()
    ' create SANE device manager
    Using deviceManager As New Vintasoft.Sane.SaneLocalDeviceManager()
        ' open SANE device manager
        deviceManager.Open()

        ' get count of SANE 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 SANE device
        Dim device As Vintasoft.Sane.SaneLocalDevice = deviceManager.Devices(0)

        ' open SANE device
        device.Open()

        Dim acquiredImage As Vintasoft.Sane.SaneAcquiredImage
        Do
            Try
                ' acquire image from SANE device
                acquiredImage = device.AcquireImageSync()
                ' if image is received
                If acquiredImage IsNot Nothing Then
                    System.Console.WriteLine("Image is acquired.")

                    ' cancel image transfer
                    device.CancelImageTransfer()
                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 device has more images to scan
        Loop While device.HasMoreImagesToScan

        ' close SANE device
        device.Close()

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

    System.Console.ReadLine()
End Sub