Dynamsoft TWAIN Products

Private Sub cmd_SelectAndAcquire_SinglePageD_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmd_SelectAndAcquire_SinglePageD.Click

    releaseTiff()

    multipage = False
    selectsource()
    twain.OpenSource()
    twain.IfShowUI = False
    twain.EnableSource()

  End Sub

  Private Sub cmd_SelectAndAcquire_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmd_SelectAndAcquire_SinglePage.Click

    releaseTiff()

    multipage = False
    selectsource()
    twain.OpenSource()
    twain.IfShowUI = True
    twain.EnableSource()

  End Sub

  Private Sub cmd_SelectAndAcquire_MultiPage_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmd_SelectAndAcquire_MultiPage.Click

    multipage = True
    selectsource()
    releaseTiff()

    Try

      If IO.Directory.Exists("tmpscan") Then ' erstmal das temp Verzeichnis löschen
        IO.Directory.Delete("tmpscan", True)
      End If
      IO.Directory.CreateDirectory("tmpscan") ' dann neu anlegen
      System.Threading.Thread.Sleep(1000)

    Catch ex As Exception
      MessageBox.Show("Fehler in der Methode: " + New StackFrame(True).GetMethod.Name.ToString + " In der Zeile: " + New StackFrame(True).GetFileLineNumber.ToString + _
    System.Environment.NewLine + "Fehler: " + ex.Message)
      Exit Sub
    End Try


    iDocumentCounter = 0

    Try

      twain.OpenSource()
      twain.IfShowUI = False

      twain.IfFeederEnabled = True

      twain.XferCount = -1
      twain.IfAutoFeed = True 'auto feed

      If twain.IfFeederLoaded = True Then
        twain.AcquireImage()
      End If


    Catch ex As Exception

      MessageBox.Show(twain.ErrorString, "Error")

    End Try

  End Sub

  Private Sub selectsource()

    If lstSources.SelectedIndex = -1 Then  'nothing is selected
      Try
        twain.SelectSourceByIndex(0)
      Catch
        MessageBox.Show("Kein Scanner verfügbar")
        Exit Sub
      End Try
    Else
      twain.SelectSourceByIndex(lstSources.SelectedIndex)
    End If

  End Sub

  Private Sub Twain_OnPostTransfer(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles twain.OnPostTransfer

    If multipage Then
      iDocumentCounter += 1

      If twain.SaveAsTiff("tmpscan\tmp" + CStr(iDocumentCounter) + ".tiff") = False Then
        MsgBox(twain.ErrorString)
      End If

      If twain.PendingXfers = 0 Then
        addTiff()
        twain.CloseSource()
        GC.Collect() 'make garbage collector work to release memory

      End If

    Else

      picImageAcquired.Image = twain.Picture
      twain.CloseSource()
      GC.Collect() 'make garbage collector work to release memory

    End If

  End Sub

  Public Sub addTiff()

    newfile = "tmpscan\" & System.Guid.NewGuid.ToString() & ".tif"

    'get the codec for tiff files
    Dim info As ImageCodecInfo = Nothing
    Dim ice As ImageCodecInfo

    For Each ice In ImageCodecInfo.GetImageEncoders()
      If ice.MimeType = "image/tiff" Then info = ice
    Next ice 'use the save encoder

    Dim enc As Encoder = Encoder.SaveFlag
    Dim ep As New EncoderParameters(1)

    ep.Param(0) = New EncoderParameter(enc, CLng(EncoderValue.MultiFrame))

    Dim pages As Bitmap = Nothing
    Dim frame As Integer = 0

    ' ----------------------------------------------------------------------

    For Each f As String In IO.Directory.GetFiles("tmpscan\", "*." & "tif")

      If frame = 0 Then 'save the first frame
        pages = CType(Image.FromFile(f), Bitmap)
        pages.Save(newfile, info, ep)
      Else 'save the intermediate frames
        ep.Param(0) = New EncoderParameter(enc, CLng(EncoderValue.FrameDimensionPage))
        Dim bm As Bitmap = CType(Image.FromFile(f), Bitmap)
        pages.SaveAdd(bm, ep)
        bm.Dispose()
      End If

      If frame = iDocumentCounter - 1 Then 'flush and close.
        ep.Param(0) = New EncoderParameter(enc, CLng(EncoderValue.Flush))
        pages.SaveAdd(ep)
      End If

      frame += 1

    Next f

    Me.picImageAcquired.Image = Image.FromFile(newfile)
    Me.picImageAcquired.Refresh()

    pages.Dispose()
    pages = Nothing

  End Sub

  Public Sub releaseTiff()

    If Not picImageAcquired.Image Is Nothing Then picImageAcquired.Image.Dispose()
    picImageAcquired.Image = Image.FromFile(Application.StartupPath & "\gotoArchiv.gif")
    If IO.File.Exists(newfile) Then File.Delete(newfile)

  End Sub