ByteScout Barcode Reader SDK – VB.NET – Parallel Barcode Decoding

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ByteScout Barcode Reader SDK – VB.NET – Parallel Barcode Decoding

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ByteScout-BarCode-Reader-SDK-VB-NET-Parallel-Barcode-Decoding.pdf

parallel barcode decoding in VB.NET with ByteScout BarCode Reader SDK

How to use ByteScout BarCode Reader SDK for parallel barcode decoding in VB.NET

Every ByteScout tool contains example VB.NET source codes that you can find here or in the folder with installed ByteScout product. Parallel barcode decoding in VB.NET can be implemented with ByteScout BarCode Reader SDK. ByteScout BarCode Reader SDK is the SDK for barcode decoding. Can read all popular types from Code 128, GS1, UPC and Code 39 to QR Code, Datamatrix, PDF417. Images, pdf, TIF images and live web camera are supported as input. Designed to handle documents with noise and defects. Includes optional splitter and merger for pdf and tiff based on barcodes. Batch mode is optimized for high performance with multiple threads. Decoded values can be exported to XML, JSON, CSV or into custom data format.

The SDK samples like this one below explain how to quickly make your application do parallel barcode decoding in VB.NET with the help of ByteScout BarCode Reader SDK. This VB.NET sample code should be copied and pasted into your application’s code editor. Then just compile and run it to see how it works. VB.NET application implementation typically includes multiple stages of the software development so even if the functionality works please test it with your data and the production environment.

Trial version can be downloaded from our website. Source code samples for VB.NET and documentation are included.

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Module1.vb

      Imports Bytescout.BarCodeReader
Imports System.Threading

Module Module1

    Const InputFile As String = ".\example.pdf"

    ' Limit to 4 threads in queue.
    ' Set this value to number of your processor cores for max performance.
    Dim ThreadLimiter As Semaphore = New Semaphore(4, 4)

    
    <MTAThread()> Sub Main()

        Const numberOfRuns As Integer = 10
        Dim doneEvents(numberOfRuns - 1) As ManualResetEvent

        For i As Integer = 0 To numberOfRuns - 1

            ' Wait for the queue
            ThreadLimiter.WaitOne()

            doneEvents(i) = New ManualResetEvent(False)

            ThreadPool.QueueUserWorkItem(New WaitCallback(AddressOf ThreadProc), New Object() {i, doneEvents(i)})

        Next

        WaitHandle.WaitAll(doneEvents)

        Console.WriteLine("All threads done.")
        Console.WriteLine()

        Console.WriteLine("Press any key to exit...")
        Console.ReadKey()

    End Sub

    Sub ThreadProc(ByVal stateInfo As Object)

        Dim threadIndex As Integer = stateInfo(0)
        Dim waitEvent As ManualResetEvent = stateInfo(1)

        Console.WriteLine("Thread #" & threadIndex & " started...")

        Try

            Dim reader As New Reader()
            reader.RegistrationName = "demo"
            reader.RegistrationKey = "demo"

            ' Set barcode type to find
            reader.BarcodeTypesToFind.Code128 = True

            ' -----------------------------------------------------------------------
            ' NOTE: We can read barcodes from specific page to increase performance .
            ' For sample please refer to "Decoding barcodes from PDF by pages" program.
            ' ----------------------------------------------------------------------- 

            ' Read barcodes
            Dim barcodes As FoundBarcode() = reader.ReadFrom(InputFile)

            ' Cleanup
            reader.Dispose()

            Console.WriteLine("Thread #" & threadIndex & " finished with " & barcodes.Length & " barcodes found.")

        Catch ex As Exception

            Console.WriteLine("Thread #" & threadIndex & " failed with exception:\r\n" & ex.Message)

        Finally

            ' Signal the thread is finished
            waitEvent.Set()

            ' Release semaphore
            ThreadLimiter.Release()

        End Try
        
    End Sub

End Module