How to Use VB.NET Code to Decode QR Code Barcodes for .NET Applications
Use professional VB.NET QR Code barcode reading & recognition library DLL
With easy-to-use design, no need for license key or registration code
Read and decode QR Code for VB.NET Windows, ASP.NET Web, and .NET Class Library projects
Read and output QR Code 2d barcodes data from image source file in high speed
Scan all QR Code barcodes or a maximum one QR Code barcode form several image file formats
Reliable VB.NET Barcode Reading Library in the market with best recognition performance
How to Implement VB.NET QR-Code Barcode Reading Library
In your VB.NET project, add BarcodeLib.BarcodeReader.dll to project reference.
How to Decode QR-Code Barcodes Using Free VB.NET Code
It's an easy task to use Visual Basic.NET code to scan QR Code barcodes from a image file. One line free VB code can achieve this.
Dim datas() AsString = BarcodeReader.read("c:/qrcode-vbnet.gif", BarcodeReader.QRCODE)
With this simple VB code, you can read and output all QR Code barcodes data in "qrcode-vbnet.gif" image file at a time.
How to Imporve QR Code Barcode Reading Using Free VB.NET Code
To optimize QR Code barcode reading effect & speed with our VB.NET Barcode Reader DLL, please do as follows. It is suitable to be adopted especially when the source image file is in a large size, like 4mb per image.
1. Scan the Maximum One QR Code Barcode from Image File
If you want to scan the maximum one QR Code in your image source (per image, page in tiff or pdf document), you may set maxOneBarcodePerPage to true.
In this condition, our VB.NET Barcode Recognition Control will stop decode the QR Code as soon as it detects one barcode.
If this property is the default value "false", our our VB.NET Barcode Recognition Control will use total 5 algorithms and each will decode the whole source file from 4 directions.
2. Scan the Partial Image of a Source File
If your QR Code barcode is always at specific area in image source file, you can directly recognize that area only. In this way, you may save a lot of scanning time, CPU and memory usage.
Please specify the left top point and right bottom point of the specific area (the point X, Y values are expressed in percentage of the whole image, so image most left top point is (0%, 0%), and most right bottom point is (100%, 100%).
We provide sample VB.NET Code for this type reading and take top 20% and bottom 20% of the image as an example.
Dim setting As OptimizeSetting = New OptimizeSetting()
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)
Dim datas() AsString = BarcodeReader.read("c:/qrcode-vbnet.gif", BarcodeReader.QRCODE, setting)