VintaSoftTwain Control v6.0
VintaSoftTwain Object / Device_CancelImageTransfer Method
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    Device_CancelImageTransfer Method
    In This Topic
    Sends the cancel current transfer command to the device (transfer will not be canceled right after execution of this method).
    Visual Basic
    Public Sub Device_CancelImageTransfer() 
    Important: Transfer will not be canceled right after execution of this method, transfer will be canceled when the DeviceScanCanceled event occurs or the Device_AcquireImageModal method returns AcquireModalState.None.

    Information about error that occurs during method execution can be get using the Error and ErrorString properties.
    Here is an example that shows how to cancel current asynchronous image transfer.
    Private VSTwain1 As New VintaSoftTwain()
    Private _isScanFinished As Boolean
    Private _isScanCanceled As Boolean
    ''' <summary>
    ''' This method scans one image and cancels image scan.
    ''' </summary>
    Private Sub ScanOneImageAndCancelScan()
        _isScanFinished = False
        _isScanCanceled = False
        VSTwain1.DeviceManager_IsTwain2Compatible = True
        ' open the device manager
        If Not VSTwain1.DeviceManager_Open() Then
            Exit Sub
        End If
        ' get the device index
        Dim deviceName As String = "KODAK Scanner: i5000"
        Dim deviceIndex As Integer = VSTwain1.DeviceManager_FindDevice(deviceName)
        If deviceIndex = -1 Then
            Throw New ApplicationException(String.Format("Device '{0}' is not found.", deviceName))
        End If
        ' select the device by index
        VSTwain1.DeviceManager_SelectedDeviceIndex = deviceIndex
        ' disable device UI
        VSTwain1.Device_ShowUI = False
        ' specify that device must be closed after scan
        VSTwain1.Device_DisableAfterAcquire = True
        ' open the device
        If Not VSTwain1.Device_Open Then
            Exit Sub
        End If
        ' specify that 2 images must be acquired from scanner
        VSTwain1.Device_XferCount = 2
        ' subscribe to the device events
        AddHandler VSTwain1.DeviceImageAcquired, AddressOf VSTwain1_ImageAcquired
        AddHandler VSTwain1.DeviceScanCompleted, AddressOf VSTwain1_ScanCompleted
        AddHandler VSTwain1.DeviceScanFailed, AddressOf VSTwain1_ScanFailed
        AddHandler VSTwain1.DeviceScanCanceled, AddressOf VSTwain1_ScanCanceled
        ' run asynchronous image acqusition
        ' wait while feeder will be stopped
        While Not _isScanFinished
        End While
        ' unsubscribe from device events
        RemoveHandler VSTwain1.DeviceImageAcquired, AddressOf VSTwain1_ImageAcquired
        RemoveHandler VSTwain1.DeviceScanCompleted, AddressOf VSTwain1_ScanCompleted
        RemoveHandler VSTwain1.DeviceScanFailed, AddressOf VSTwain1_ScanFailed
        RemoveHandler VSTwain1.DeviceScanCanceled, AddressOf VSTwain1_ScanCanceled
        ' close the device
        If Not _isScanCanceled Then
            Throw New ApplicationException("Scan is NOT canceled.")
        End If
    End Sub
    Private Sub VSTwain1_ImageAcquired()
        Console.WriteLine("Image is acquired.")
        ' cancel image scan
    End Sub
    Private Sub VSTwain1_ScanCompleted()
        Console.WriteLine("Scan is completed.")
        _isScanFinished = True
    End Sub
    Private Sub VSTwain1_ScanFailed(errorString As String)
        Console.WriteLine(String.Format("Scan is failed: {0}.", errorString))
        _isScanFinished = True
    End Sub
    Private Sub VSTwain1_ScanCanceled()
        _isScanCanceled = True
        Console.WriteLine("Scan is canceled.")
        _isScanFinished = True
    End Sub
    See Also