Xojo Plugin Requires Chilkat v11.7.0+

Get the Modules of a QR Code (Bit Matrix)

See more QR Code Examples

Demonstrates getting the QR code itself, as a grid of dark and light modules, to draw with something other than the built-in PNG and SVG output: on a canvas, in a PDF, on a display, or with a label printer language. With output.includeModuleData the response has symbols[0].moduleData, a bit matrix with one bit per module, each row starting on a new byte, most significant bit first, 1 for dark. The quiet zone is not part of the matrix. The example prints the symbol using two characters per module. Xojo Plugin

Dim success As Boolean
success = False

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

Dim json As New Chilkat.JsonObject
success = json.UpdateString("payload.text","CHILKAT")
success = json.UpdateBool("output.includeModuleData",True)

Dim fmt As New Chilkat.Formats
Dim jsonOut As New Chilkat.JsonObject
success = fmt.QrCode("generate",json,jsonOut)
If (success = False) Then
    System.DebugLog(fmt.LastErrorText)
    Return
End If

Dim width As Int32
width = jsonOut.IntOf("symbols[0].moduleData.width")
Dim height As Int32
height = jsonOut.IntOf("symbols[0].moduleData.height")
Dim rowBytes As Int32
rowBytes = jsonOut.IntOf("symbols[0].moduleData.rowBytes")
System.DebugLog("kind: " + jsonOut.StringOf("symbols[0].moduleData.kind"))
System.DebugLog("modules: " + Str(width) + " x " + Str(height) + ", " + Str(rowBytes) + " bytes per row")

//  The matrix is height rows of rowBytes bytes.
Dim bd As New Chilkat.BinData
success = bd.AppendEncoded(jsonOut.StringOf("symbols[0].moduleData.bytesBase64"),"base64")
If (success = False) Then
    System.DebugLog(bd.LastErrorText)
    Return
End If

Dim sbRow As New Chilkat.StringBuilder
Dim row As Int32
Dim col As Int32
Dim b As Int32
Dim mask As Int32
mask = 128
For row = 0 To height - 1
    sbRow.Clear 
    For col = 0 To width - 1
        //  The module at (col,row) is a bit of the byte at (row * rowBytes) + (col / 8).
        //  The leftmost module of each byte is its most significant bit.
        If ((col Mod 8) = 0) Then
            mask = 128
        End If

        b = bd.GetByte((row * rowBytes) + (col / 8))
        If (((b / mask) Mod 2) = 1) Then
            success = sbRow.Append("##")
        Else
            success = sbRow.Append("  ")
        End If

        mask = mask / 2
    Next
    System.DebugLog(sbRow.GetAsString())
Next

//  The same symbol as the PNG that the call also returned:

//  

//  Sample output:

//  kind: bitMatrix
//  modules: 21 x 21, 3 bytes per row
//  ##############              ##############
//  ##          ##      ####    ##          ##
//  ##  ######  ##  ##  ####    ##  ######  ##
//  ##  ######  ##  ##          ##  ######  ##
//  ##  ######  ##  ##  ##  ##  ##  ######  ##
//  ##          ##  ####  ##    ##          ##
//  ##############  ##  ##  ##  ##############
//                  ####
//  ##  ##########      ####    ##########
//      ####          ##  ########    ######
//  ####  ########    ####  ##  ####      ####
//        ##  ##      ############    ####  ##
//    ######  ####  ######  ##    ##  ##
//                  ##  ##  ##    ##  ##    ##
//  ##############        ##  ##    ##      ##
//  ##          ##  ##  ##        ######  ####
//  ##  ######  ##  ####  ##  ##    ##
//  ##  ######  ##  ##  ############    ##
//  ##  ######  ##  ##      ##  ####  ##
//  ##          ##    ##  ########          ##
//  ##############  ##      ##      ######