VB.NET QR Code Reader & Scanner SDK


How to scan, read QR Code barcode images in Visual Basic .NET Windows application?

How to read, scan, decode QR Code 2d barcode images in VB.NET class, ASP.NET Web & Windows applications

  • Scan QR Code and GS1 QR Code barcode in VB.NET class, Console applications
  • Read QR Code barcode in VB.NET ASP.NET web projects
  • Read, decode QR Code images in Visual Studio VB.NET Windows Forms applications
  • Easy and simple to integrate QR Code reader component (single dll file) into your VB.NET project
  • Detailed tutorials on read barcode in asp.net core web app using c#, read barcode in c# windows application
  • Complete developed in C# 2005, for .net framework 2.0 and later version
  • Scanning, decoding QR Code from multiple image formats, like BMP, GIF, JPEG, PNG, TIFF formats
  • Scanning, reading QR Code from multi-page TIFF documents

How to read, scan QR Code image in VB.NET application

  1. Download .NET QR Code Reader Library
  2. Install VB.NET library to scan barcode images in VB.NET apps
  3. Step by Step Tutorial












Scan, Read QR Code barcodes from images is one of the barcode reading functions in .NET Barcode Reader SDK control. It is compatible for Microsoft Visual Studio .NET framework 2.0 and later version. VB.NET barcode scanner is a robust and mature .net barcode recognition component for VB.NET projects. You can easily scan and decode linear, 2d barcodes from image documents in your VB.NET class, console application, ASP.NET web projects, and VB.NET Windows software.
To help .net developers easiy integrate barcode reader control into your .net projects, we provide detailed online tutorial for
VB.NET Barcode Reader component supports scanning and reading 20+ linear, 2d barcodes, including
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Quick to scan QR Codes in VB.NET WinForms, WPF application

You can implement fast QR Code scanning in your VB.NET application with a single method call.

This method returns raw QR Code text messages directly.

  1. Call the core scanning method BarcodeScanner.Scan().
  2. Pass the QR Code image file path as the first parameter.
  3. Set the barcode type to BarcodeType.QRCode.
  4. The method returns a string array containing all decoded QR Code data.

' Scan QR Code from image and get raw text data
Dim datas As String() = BarcodeScanner.Scan("qrcode-sample.png", BarcodeType.QRCode)



Scan multiple QR Codes from an image file in VB.net

OnBarcode VB.NET Barcode Reader library will automatically scan and recognize all QR Codes from a single image file in VB program.





Scan and read all QR Code informations from image in VB.NET

Here we will learn how to retrieve detailed QR Code metadata and extract advanced barcode properties using VB.NET.

You can obtain full barcode metadata by calling BarcodeScanner.ScanInDetails().

This method returns an array of BarcodeDetail (barcode metadata entity) objects containing complete scanning information.

  1. Call BarcodeScanner.ScanInDetails() with the image path and barcode type.
  2. The method returns detailed QR Code information including location and rotation.

' Scan QR Code and retrieve detailed barcode information
Dim datasInDetail As BarcodeDetail() = BarcodeScanner.ScanInDetails(
    "qrcode-sample.png", BarcodeType.QRCode)




Process scanned QR Code data message in VB.NET Windows applications

QR Code supports a wide range of character sets and industry-standard data structures.

The VB.NET Barcode Reader library provides dedicated methods to parse and process these complex data types.

You can use built-in functions to handle multiple encoding formats efficiently.

Supported Character Sets & Data Formats

The library supports processing the following formats from scanned QR Codes:

  • ASCII text
    Includes both printable and non-printable characters.
  • Unicode text
    Supports multi-language and universal character encoding.
  • Binary data
    Supports raw byte data for files, streams, and custom payloads.
  • GS1 data elements
    Supports industry-standard GS1-compliant barcode messages.




ASCII text characters

We will explain how to scan QR Code (2D matrix barcode) images and process ASCII text (American Standard Code for Information Interchange, including printable and non-printable characters) using VB.NET.

Full ASCII text table consists of 128 standard characters.The first 32 characters and the final character are non-printable control characters. One common example is the carriage return control character.

You can scan QR Codes and format non-printable ASCII characters into readable labels in VB.NET applications.

  1. Call BarcodeScanner.Scan() to decode the QR Code image.
  2. Check if valid barcode results are returned.
  3. Iterate through the scanned text messages.
  4. Replace non-printable carriage return characters (\r) with a visible label [CR].
  5. Output both raw and formatted text values.

' Scan QR Code and get ASCII text results
Dim result As String() = BarcodeScanner.Scan(
    "C:\Input\qrcode-ascii-sample.png", BarcodeType.QRCode)

' Check if any QR Code is detected
If result.Length > 0 Then
    ' Process each scanned message
    For Each msg As String In result
        Debug.WriteLine("QR Code Raw Message: '" & msg & "'")
        ' Replace carriage return non-printable character with [CR] label
        Dim tmp As String = msg.Replace(vbCr, "[CR]")
        Debug.WriteLine("QR Code ASCII Text: '" & tmp & "'")
    Next
Else
    Debug.WriteLine("No QR Code Scanned!")
End If




Unicode text

QR Code supports Unicode text encoding. Most barcode generators and printers convert Unicode text to binary data. They then encode the binary data using QR Code binary mode.

To decode Unicode text correctly, you must use the matching encoding format. UTF8 encoding is the most common standard for Unicode QR Codes.

You can extract and decode Unicode text from QR Code using UTF8 encoding in VB.NET.

  1. Call BarcodeScanner.ScanInDetails() to read the QR Code image.
  2. Use GetDataBytes() to retrieve raw binary data from the barcode.
  3. Decode the byte array using System.Text.Encoding.UTF8.
  4. Output the readable Unicode text result.

' Scan QR Code and retrieve detailed barcode information
Dim datas As BarcodeDetail() = BarcodeScanner.ScanInDetails(
    "C:\Input\qrcode-unicode.png", BarcodeType.QRCode)

' Loop through all scanned barcode results
For j As Integer = 0 To datas.Length - 1
    ' Decode binary data to Unicode text using UTF8 encoding
    Dim textMsgDecoded As String = System.Text.Encoding.UTF8.GetString(datas(j).GetDataBytes())
    ' Output decoded Unicode text
    Console.WriteLine("Unicode text: " & textMsgDecoded)
Next





GS1 data message

The GS1 System uses QR Code as a common data carrier. A GS1-encoded QR Code contains pairs of AI (Application Identifier, standard GS1 identification code) and corresponding data. It may also include control characters like the Function 1 Symbol Character (FNC1).

The VB.NET Barcode Reader library automatically parses GS1 messages. You can directly read formatted GS1 data elements without handling low-level control characters.

Follow these steps to implement GS1 QR Code scanning and parsing in VB.NET:

  1. Call BarcodeScanner.ScanInDetails() to load and scan the GS1 QR Code image.
  2. Check the IsGS1Compatible property to verify GS1 compliance.
  3. Use the GetMessage() method to retrieve formatted GS1 text.
  4. Split the result to extract individual AI and data pairs.
  5. Output structured GS1 elements for further processing.

' Scan GS1 QR Code and get detailed barcode information
Dim result As BarcodeDetail() = BarcodeScanner.ScanInDetails(
    "C:\Input\qrcode-gs1-data.png", BarcodeType.QRCode)

' Iterate all scanned barcode results
For Each b As BarcodeDetail In result
    ' Check if the barcode conforms to the GS1 standard
    If b.IsGS1Compatible Then
        ' Get formatted GS1 message (Example: (415)5412345678908(3911)710125)
        Dim msg As String = b.GetMessage()
        
        ' Output raw barcode data and formatted message
        Console.WriteLine("Raw Data: '{0}'", b.Data)
        Console.WriteLine("Text Message: {0}", msg)

        ' Split AI and data pairs using ( and ) delimiters
        Dim vals As String() = msg.Split({"("c, ")"c}, StringSplitOptions.RemoveEmptyEntries)

        ' Extract and display AI and corresponding data in pairs
        For i As Integer = 0 To vals.Length - 1 Step 2
            Console.WriteLine("AI:    {0}", vals(i))
            Console.WriteLine("Data:  {0}", vals(i + 1))
        Next
    End If
Next





How to scan QR Code with logo image in VB.NET?

OnBarcode .NET Barcode Reader library supports scanning QR Code with logo image inside. The barcode library will automatically read and detect colored QR Code with logo image inside.

Dim datas As String() = BarcodeScanner.Scan("qrcode-logo-image.png", BarcodeType.QRCode)





How to improve QR Code image reading performance in VB.NET Windows application?

The VB.NET Barcode Reader library offers multiple optimized methods to improve scanning efficiency. These features reduce processing time and enhance responsiveness in desktop applications.

  • Single QR Code Quick Scan
    When enabled, the library stops scanning immediately after detecting the first valid QR Code. This eliminates unnecessary full-image processing.
  • Concurrent Multi-Type Barcode Scanning
    Supports scanning QR Code and other barcode symbologies in a single operation.
  • Specified Region Scanning
    Restricts scanning to defined rectangular areas of the image. This reduces the total pixel data that must be processed.




Scan a single QR Code

The VB.NET Barcode Reader library provides an optimized fast-scan feature.

When this feature is enabled, the scanning process stops immediately after detecting a valid QR Code.

This greatly reduces unnecessary processing and improves decoding speed.

This function is highly efficient for images that contain only one QR Code symbol.

  1. Use the dedicated method BarcodeScanner.ScanSingleBarcode().
  2. Pass the image path and set the barcode type to BarcodeType.QRCode.
  3. The scanner stops automatically after detecting the first QR Code.
  4. Return the decoded barcode text as a string array.

' Scan and return only the first detected QR Code (fast mode)
Dim barcodes As String() = BarcodeScanner.ScanSingleBarcode(
    "qrcode-single-barcode.png", BarcodeType.QRCode)




Scan multiple QR Codes with other barcode formats

The VB.NET Barcode Reader library supports scanning multiple barcode types in one operation. You can scan custom selected formats or all supported formats in a single pass. You can also use BarcodeType.All to enable full library support.

Scan specific barcode formats from one image for efficiency and accuracy.

  1. Call the BarcodeScanner.ScanInDetails() method to load the image and start decoding.
  2. Pass a custom list of required barcode types as the scanning parameter.
  3. The library automatically identifies and decodes all matching barcodes in the image.
  4. Retrieve complete barcode metadata via the BarcodeDetail (barcode information entity) array.

' Scan QR Code, GS1-128 (Code 128), EAN-13 barcodes simultaneously
Dim datas As BarcodeDetail() = BarcodeScanner.ScanInDetails("qrcode-multiple-formats.png",
    New List(Of BarcodeType) From {
    BarcodeType.QRCode, BarcodeType.Code128, BarcodeType.EAN13})





Scan image regions to read QR Codes

You can define rectangular areas inside an image to limit the scanning scope. This improves reading speed and reduces decoding errors. The barcode library only processes the specified regions instead of the full image. This optimization works for QR Code and all other supported barcode symbologies.

VB.NET code to scan multiple barcodes within predefined regions using ScanRegions().

  1. Create a list of SRegion objects to define scanning areas.
  2. Add region coordinates (X, Y, Width, Height).
  3. Call BarcodeScanner.ScanRegions() with the image path, barcode type, and region list.
  4. Retrieve all detected barcodes as a string array.

' Define multiple scanning regions
Dim regions As New List(Of SRegion)()
regions.Add(New SRegion(0, 0, 50, 60))
regions.Add(New SRegion(100, 100, 50, 60))

' Scan QR Code only from specified regions
Dim barcodes As String() = BarcodeScanner.ScanRegions("qrcode-barcodes.png",
    BarcodeType.QRCode, regions)












Common Asked Questions

How to read QR Code on desktop?

You can use barcode scanner software installed on computer or barcode scanner device to read and extract QR Code from image. OnBarcode VB.net QR Code Reader library supports building Windows application with QR Code scanning and reading functions with few lines of Visual Basic source codes.

How to read a QR code that's on your screen?

To read a QR Code on your screen, try the following steps
  • Take and save the screenshot of the QR Code image on the computer
  • Use QR Code scanner software to read the QR Code from the image
VB.NET QRCode Reader library supports Visual Basic developers quickly to build a Windows (WinForms, WPF, or Console) application with QR Code decoder features integrated.

How do I scan a QR code with my phone?

You can download and install QR Code Scanner app on the iPhone or Android phones. OnBarcode VB.NET QR Code Scanner library supports building Xamarin application for iOS and Adroid with QR Code reading functions.

How do you scan a QR code from an image?

Online QR Code decoder, QR Code Scanner software allow you to scan and extract a QR Code from an images. Using OnBarcode QR Code Reader VB.NET SDK, you can quickly build online QR Code scanner based on Windows QR Code Scanner software using WinForms or WPF framework using VB.

Is there a scanner or reader for QR codes?

You can use iPhone and Android phone build-in QR Code Scanner app to read the QR Codes. If you are VB.NET developer, you can easily build app for iOS and Android with QR Code Reader embed using VB.NET Barcode Reader library with Xamarin.




































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