Private VSTwain1 As New VintaSoftTwain()


''' <summary>
''' Scans images synchronously.
''' </summary>
Public Sub ScanImages()
    ' specify name of scanning application
    VSTwain1.DeviceManager_ApplicationProductName = "MyTwainApplication"
    ' open the device manager
    If Not VSTwain1.DeviceManager_Open() Then
        Console.WriteLine(VSTwain1.errorString)
        Exit Sub
    End If

    ' select device using standard device selection dialog
    VSTwain1.DeviceManager_ShowDefaultDeviceSelectionDialog()

    ' open the device
    If Not VSTwain1.Device_Open Then
        Console.WriteLine(VSTwain1.errorString)
        Exit Sub
    End If

    ' specify that device UI must be shown
    VSTwain1.Device_ShowUI = True

    ' specify that acquired image must be added to an existing TIFF file
    VSTwain1.TiffEncoder_MultiPage = True

    ' run synchronous image acquisition
    Dim acquireModalState1 As VSTwainLib.ACQUIREMODALSTATE = ACQUIREMODALSTATE.AcquireModalState_None
    Do
        acquireModalState1 = VSTwain1.Device_AcquireImageModal()
        Select Case acquireModalState1
            Case ACQUIREMODALSTATE.AcquireModalState_ImageAcquired
                Console.WriteLine("Image is acquired.")

                ' save acquired image to TIFF file
                If Not VSTwain1.AcquiredImages_Save(0, "test.tif") Then
                    Console.WriteLine(VSTwain1.errorString)
                End If

                ' delete image from internal image buffer
                VSTwain1.AcquiredImages_Clear()
                Exit Select

            Case ACQUIREMODALSTATE.AcquireModalState_ScanCompleted
                Console.WriteLine("Scan is completed.")
                Exit Select

            Case ACQUIREMODALSTATE.AcquireModalState_ScanCanceled
                Console.WriteLine("Scan is canceled.")
                Exit Select

            Case ACQUIREMODALSTATE.AcquireModalState_ScanFailed
                Console.WriteLine(String.Format("Scan is failed: {0}.", VSTwain1.errorString))
                Exit Select
        End Select
    Loop While acquireModalState1 <> ACQUIREMODALSTATE.AcquireModalState_None
End Sub