Class SyncScan_Cancel

        ''' <summary>
        ''' This method scans one image and cancels image scan.
        ''' </summary>
        Public Shared Sub ScanOneImageAndCancelScan()
                Dim isScanCanceled As Boolean = False

                ' create the device manager
                Using deviceManager As New Vintasoft.Twain.DeviceManager()
                        deviceManager.IsTwain2Compatible = True
                        ' open the device manager
                        deviceManager.Open()

                        ' get the device
                        Dim deviceName As String = "KODAK Scanner: i5000"
                        Dim device As Vintasoft.Twain.Device = deviceManager.Devices.Find(deviceName)
                        If device Is Nothing Then
                                Throw New ApplicationException(String.Format("Device '{0}' is not found.", deviceName))
                        End If

                        ' disable device UI
                        device.ShowUI = False
                        ' specify that device must be closed after scan
                        device.DisableAfterAcquire = True

                        ' open the device
                        device.Open()
                        ' specify that 2 images must be acquired from scanner
                        device.XferCount = 2

                        ' run asynchronous image acquisition
                        Dim acquireModalState1 As Vintasoft.Twain.AcquireModalState = Vintasoft.Twain.AcquireModalState.None
                        Do
                                acquireModalState1 = device.AcquireModal()
                                Select Case acquireModalState1
                                        Case Vintasoft.Twain.AcquireModalState.ImageAcquired
                                                Console.WriteLine("Image is acquired.")
                                                If device.AcquiredImage IsNot Nothing Then
                                                        device.AcquiredImage.Dispose()
                                                End If

                                                ' cancel image scan
                                                device.CancelTransfer()
                                                Exit Select

                                        Case Vintasoft.Twain.AcquireModalState.ScanCompleted
                                                Console.WriteLine("Scan is completed.")
                                                Exit Select

                                        Case Vintasoft.Twain.AcquireModalState.ScanCanceled
                                                isScanCanceled = True
                                                Console.WriteLine("Scan is canceled.")
                                                Exit Select

                                        Case Vintasoft.Twain.AcquireModalState.ScanFailed
                                                Console.WriteLine(String.Format("Scan is failed: {0}.", device.ErrorString))
                                                Exit Select
                                End Select
                        Loop While acquireModalState1 <> Vintasoft.Twain.AcquireModalState.None

                        If Not isScanCanceled Then
                                Throw New ApplicationException("Scan is NOT canceled.")
                        End If

                        ' close the device
                        device.Close()
                End Using
        End Sub

End Class

namespace TwainExamples_CSharp
{
    class SyncScan_Cancel
    {

        /// <summary>
        /// This method scans one image and cancels image scan.
        /// </summary>
        public static void ScanOneImageAndCancelScan()
        {
            bool isScanCanceled = false;

            // create the device manager
            using (Vintasoft.Twain.DeviceManager deviceManager = new Vintasoft.Twain.DeviceManager())
            {
                deviceManager.IsTwain2Compatible = true;
                // open the device manager
                deviceManager.Open();

                // get the device
                string deviceName = "KODAK Scanner: i5000";
                Vintasoft.Twain.Device device = deviceManager.Devices.Find(deviceName);
                if (device == null)
                    throw new System.ApplicationException(string.Format("Device '{0}' is not found.", deviceName));

                // disable device UI
                device.ShowUI = false;
                // specify that device must be closed after scan
                device.DisableAfterAcquire = true;

                // open the device
                device.Open();
                // specify that 2 images must be acquired from scanner
                device.XferCount = 2;

                // run asynchronous image acquisition
                Vintasoft.Twain.AcquireModalState acquireModalState = Vintasoft.Twain.AcquireModalState.None;
                do
                {
                    acquireModalState = device.AcquireModal();
                    switch (acquireModalState)
                    {
                        case Vintasoft.Twain.AcquireModalState.ImageAcquired:
                            System.Console.WriteLine("Image is acquired.");
                            if (device.AcquiredImage != null)
                                device.AcquiredImage.Dispose();

                            // cancel image scan
                            device.CancelTransfer();
                            break;

                        case Vintasoft.Twain.AcquireModalState.ScanCompleted:
                            System.Console.WriteLine("Scan is completed.");
                            break;

                        case Vintasoft.Twain.AcquireModalState.ScanCanceled:
                            isScanCanceled = true;
                            System.Console.WriteLine("Scan is canceled.");
                            break;

                        case Vintasoft.Twain.AcquireModalState.ScanFailed:
                            System.Console.WriteLine(string.Format("Scan is failed: {0}.", device.ErrorString));
                            break;
                    }
                }
                while (acquireModalState != Vintasoft.Twain.AcquireModalState.None);

                if (!isScanCanceled)
                    throw new System.ApplicationException("Scan is NOT canceled.");

                // close the device
                device.Close();
            }
        }

    }
}