使用GdPicture.NET可以快速讀取PDF文檔中的1D和2D碼，下面給出示例代碼。

1 讀取PDF文檔中的1D碼

   
      'Step1: Open the PDF
      Dim oGdPicturePDF As New GdPicture.GdPicturePDF
      If oGdPicturePDF.LoadFromFile("c:\test.pdf", False) = GdPictureStatus.OK Then
         'Step2: Convert the desired PDF page to GdPicture Image
         oGdPicturePDF.SelectPage(1)
         Dim ImageID As Integer = oGdPicturePDF.RenderPageToGdPictureImage(200, False)
         If ImageID <> 0 Then
            'Step3: Barcode recognition from GdPicture Image
            Dim oGdPictureImaging As New GdPicture.GdPictureImaging
            oGdPictureImaging.Barcode1DReaderDoScan(ImageID, Barcode1DReaderScanMode.BestQuality)
            oGdPictureImaging.ReleaseGdPictureImage(ImageID)
            For i As Integer = 1 To oGdPictureImaging.Barcode1DReaderGetBarcodeCount
               MsgBox("Barcode no: " + Str(i) + Chr(13) + _
                      "Barcode type: " + oGdPictureImaging.Barcode1DReaderGetBarcodeType(i).ToString + Chr(13) + _
                      "Barcode angle: " + Str(oGdPictureImaging.Barcode1DReaderGetBarcodeSkewAngle(i)) + Chr(13) + _
                      "Barcode value: " + oGdPictureImaging.Barcode1DReaderGetBarcodeValue(i))
            Next
            oGdPictureImaging.Barcode1DReaderClear()
            oGdPictureImaging.Dispose()
         End If
         oGdPicturePDF.CloseDocument()
      End If

2 讀取PDF文檔中的Datamatrix碼

   
      'Step1: Open the PDF
      Dim oGdPicturePDF As New GdPicture.GdPicturePDF
      If oGdPicturePDF.LoadFromFile("c:\test.pdf", False) = GdPictureStatus.OK Then
         'Step2: Convert the desired PDF page to GdPicture Image
         oGdPicturePDF.SelectPage(1)
         Dim ImageID As Integer = oGdPicturePDF.RenderPageToGdPictureImage(200, False)
         If ImageID <> 0 Then
            'Step3: Barcode recognition from GdPicture Image
            Dim oGdPictureImaging As New GdPicture.GdPictureImaging
            oGdPictureImaging.BarcodeDataMatrixReaderDoScan(ImageID, BarcodeDataMatrixReaderScanMode.BestQuality)
            oGdPictureImaging.ReleaseGdPictureImage(ImageID)
            For i As Integer = 1 To oGdPictureImaging.BarcodeDataMatrixReaderGetBarcodeCount
               MsgBox("Barcode no: " + Str(i) + Chr(13) + _
                      "Barcode columns: " + oGdPictureImaging.BarcodeDataMatrixReaderGetBarcodeColumns(i).ToString + Chr(13) + _
                      "Barcode rows: " + Str(oGdPictureImaging.BarcodeDataMatrixReaderGetBarcodeRows(i)) + Chr(13) + _
                      "Barcode value: " + oGdPictureImaging.BarcodeDataMatrixReaderGetBarcodeValue(i))
            Next
            oGdPictureImaging.BarcodeDataMatrixReaderClear()
            oGdPictureImaging.Dispose()
         End If
         oGdPicturePDF.CloseDocument()
      End If