Please integrate "BarcodeLib.BarcodeReader.dll" into your Visual Basic .NET project reference.
Use VB.NET Class Code to Read Code 39 1D Barcode Image
Dim datas() AsString = BarcodeReader.read("c:/code39-vbnet.gif", BarcodeReader.CODE39)
With above VB.NET code, all Code 39 barcodes from target image source (code39-vbnet.gif) will be read & decoded.
Optimize Code 39 Barcode Scanning Effects in VB.NET Projects
Set maxOneBarcodePerPage to true when you are scanning a maximum Code 39 barcode from an image file
Then the reader will not read the whole source image from 4 directions with total five algorithms. Instead, it will stop reading & decoding after it detects one Code 39 barcode image.
Read & decode Code 39 barcode by just scanning partial image file
Actually, the whole target image file can be counted as an area formed by two axes. And our VB.NET Code 39 barcode reader specifies the most left top point as (0%, 0%), and the most right bottom point as (100%, 100%).
Thus, users could easily locate an area with following VB.NET class codes: (The VB.NET codes below are used to scan & read the Code 39 barcodes in the top 20% and bottom 20% area.)
Dim setting As OptimizeSetting = New OptimizeSetting()
setMaxOneBarcodePerPage(True)
Dim top20 As ScanArea = New ScanArea(New Drawing.PointF(0.0F, 0.0F), New Drawing.PointF(100.0F, 20.0F))
Dim bottom20 As ScanArea = New ScanArea(New Drawing.PointF(0.0F, 80.0F), New Drawing.PointF(100.0F, 100.0F))
Dim areas As List(Of ScanArea) = New List(Of ScanArea) areas.Add(top20) areas.Add(bottom20)
setting.setAreas(areas)
Dim datas() AsString = BarcodeReader.read("c:/code39-vbnet.gif", BarcodeReader.CODE39, setting)