Qr Code In Vb6 (2025)

Method 1: Using QRCodeLib (Recommended)

First, download QRCodeLib from GitHub or other sources. Then add reference to your project.

' Add reference: Project -> References -> "QRCodeLib"

Private Sub Command1_Click()
Dim QR As QRCodeLib.QRCode
Set QR = New QRCodeLib.QRCode


' Create QR code image
Dim img As stdole.IPictureDisp
Set img = QR.EncodeData("Your text here", 10) ' 10 = size/version
' Save to file
SavePicture img, "C:\qrcode.bmp"
' Display in picturebox
Picture1.Picture = img



End Sub

Step 4: Generate a QR Code in Code

Private Sub Command1_Click()
    Dim qr As New QRCodeGenerator.QRCode
    Dim bmp As stdole.IPictureDisp

' Generate QR code from text
Set bmp = qr.MakeQRCode("Hello from VB6! Product #12345")
' Display in PictureBox
Picture1.Picture = bmp
' Optional: Save to file
SavePicture Picture1.Image, "C:\QR_Output.bmp"



End Sub

Pros: Fast, offline, professional output.
Cons: Requires finding a stable, modern VB6-compatible DLL (many are paid or abandonware). qr code in vb6

Conclusion

QR codes in VB6 are not only possible but practical for modernizing legacy applications. You have three clear paths:

  1. DLL Integration (fastest, most robust) – recommended for production.
  2. Web API (easiest to prototype, no installation) – good for internal tools with internet.
  3. Pure VB6 (academic, challenging) – only for learning or extremely restricted environments.

The era of QR codes is far from over, and VB6 remains capable of participating in this ecosystem. Start with a simple DLL or web call today, and your old VB6 app will be scanning and printing QR codes like a modern .NET application.

Option C: Online Decoding API

Send the image to a web service like https://api.qrserver.com/v1/read-qr-code/.

' Use MSXML2 to POST a multipart form (advanced)
' See Part 3 for similar HTTP logic.

Decoding QR codes (reading)

Options:

  1. Use a CLI decoder (zxing, zbarimg) and read stdout via Shell or temp file.
  2. Use a COM/ActiveX decoder (zxing .NET wrapped for COM, commercial SDKs).
  3. Send image to a web API that returns decoded text.

VB6 example calling zbarimg (CLI) and reading output file:

Private Function DecodeQRCode_CLI(imagePath As String) As String
    Dim cmd As String, tmp As String
    tmp = App.Path & "\qrdout.txt"
    cmd = "zbarimg -q --raw """ & imagePath & """ > """ & tmp & """"
    Shell cmd, vbHide
    ' Wait and read (simple)
    Dim fnum As Integer
    fnum = FreeFile
    On Error Resume Next
    Open tmp For Input As #fnum
    DecodeQRCode_CLI = ""
    If Err = 0 Then
        Line Input #fnum, DecodeQRCode_CLI
        Close #fnum
    End If
    Kill tmp
End Function

Notes:

Step 2: Register the DLL

On your development machine (or deployment PC), register the DLL using:

regsvr32 QRCodeGen.dll

Method 2: Using Google Charts API (Online)

Private Sub GenerateQRCode_API(ByVal Text As String, ByVal Size As Integer)
    Dim URL As String
    Dim XMLHttp As Object
    Dim ByteData() As Byte

' Google Charts API URL
URL = "https://chart.googleapis.com/chart?chs=" & Size & "x" & Size & _
      "&cht=qr&chl=" & URLEncode(Text) & "&choe=UTF-8"
' Download image
Set XMLHttp = CreateObject("MSXML2.XMLHTTP")
XMLHttp.Open "GET", URL, False
XMLHttp.Send
If XMLHttp.Status = 200 Then
    ByteData = XMLHttp.responseBody
    SaveByteArrayToFile ByteData, "C:\qrcode.png"
    Picture1.Picture = LoadPicture("C:\qrcode.png")
End If



End Sub


Private Function URLEncode(ByVal Text As String) As String
Dim i As Integer
Dim ch As String


URLEncode = ""
For i = 1 To Len(Text)
    ch = Mid(Text, i, 1)
    If (ch Like "[A-Za-z0-9]") Or (ch = ".") Or (ch = "-") Or (ch = "_") Then
        URLEncode = URLEncode & ch
    ElseIf ch = " " Then
        URLEncode = URLEncode & "+"
    Else
        URLEncode = URLEncode & "%" & Hex(Asc(ch))
    End If
Next i



End Function


Private Sub SaveByteArrayToFile(ByRef Data() As Byte, ByVal FilePath As String)
Dim FileNum As Integer
FileNum = FreeFile
Open FilePath For Binary As FileNum
Put #FileNum, , Data
Close FileNum
End Sub

The VB6 Hurdle

To bridge this gap, we have three primary strategies:

  1. Use an external DLL (e.g., ZXing C++ wrapper, QRCodeGenerator DLL).
  2. Call a Web API (generate QR codes via an online service).
  3. Implement a pure VB6 algorithm (educational, but complex for high error correction).

Approach A — Generate with a command-line tool (recommended for simplicity)

Concept: call a command-line QR generator (e.g., qrencode, zxing-cli, or any EXE that produces PNG) from VB6, then load the PNG into a PictureBox or Image.

Steps:

  1. Bundle a QR CLI EXE (qrencode, zxing, etc.) with your app.
  2. Build a command string and run it with Shell.
  3. Wait for process completion (optional) and load image.

VB6 example (using Shell and LoadPicture):

Private Sub GenerateQRCode_CLI(text As String, outPath As String)
    Dim cmd As String
    Dim pid As Long
    cmd = "qrencode -o """ & outPath & """ -s 4 -m 1 """ & Replace(text, """", "\""") & """"
    pid = Shell(cmd, vbHide)
    ' Simple wait — not robust for long tasks
    DoEvents
    ' Load into PictureBox1
    PictureBox1.Picture = LoadPicture(outPath)
End Sub

Notes: