Private VSTwain1 As New VintaSoftTwain()
Private jobsCounter As Integer
''' <summary>
''' Scans images asynchronously.
''' </summary>
Private Sub ScanImages()
' open the device manager
If Not VSTwain1.DeviceManager_Open() Then
Console.WriteLine(VSTwain1.errorString)
Exit Sub
End If
' open the device
If Not VSTwain1.Device_Open Then
Console.WriteLine(VSTwain1.errorString)
Exit Sub
End If
' scan images without UI
VSTwain1.Device_ShowUI = False
' specify that acquired image must be added to an existing TIFF file
VSTwain1.TiffEncoder_MultiPage = True
' initialize the job counter
jobsCounter = 0
' specify that device must detect and include job separator and continue scanning
VSTwain1.Device_JobControl = 1
' 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
' acquire images asynchronously
VSTwain1.Device_AcquireImage()
End Sub
Private Sub VSTwain1_ImageAcquired()
If VSTwain1.Device_EndOfJob = 1 Then
jobsCounter = jobsCounter + 1
Else
' get index of acquired image
Dim imageIndex As Integer = VSTwain1.AcquiredImages_Count - 1
' save acquired image to TIFF file
If Not VSTwain1.AcquiredImages_Save(imageIndex, "test.tiff") Then
Console.WriteLine(VSTwain1.errorString)
End If
End If
End Sub
Private Sub VSTwain1_ScanCompleted()
Console.WriteLine("Scan is completed.")
End Sub
Private Sub VSTwain1_ScanFailed(errorString As String)
Console.WriteLine(String.Format("Scan is failed: {0}.", errorString))
End Sub
Private Sub VSTwain1_ScanCanceled()
Console.WriteLine("Scan is canceled.")
End Sub