PowerBuilder Requires Chilkat v11.7.0+

QR Code Error Correction Levels

See more QR Code Examples

Demonstrates the four QR error-correction levels. L, M, Q and H allow a reader to recover the data when about 7%, 15%, 25% and 30% of the symbol is damaged or covered. More error correction leaves less room for data, so the same text needs a larger symbol at a higher level. The default is M. The example also shows boostErrorCorrection, which raises the level for free when the chosen version has room to spare. PowerBuilder

integer li_rc
long li_Success
oleobject loo_Fmt
oleobject loo_Json
oleobject loo_JsonOut
oleobject loo_Levels
long i
oleobject loo_Json2

li_Success = 0

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

loo_Fmt = create oleobject
li_rc = loo_Fmt.ConnectToNewObject("Chilkat.Formats")
if li_rc < 0 then
    destroy loo_Fmt
    MessageBox("Error","Connecting to COM object failed")
    return
end if
loo_Json = create oleobject
li_rc = loo_Json.ConnectToNewObject("Chilkat.JsonObject")

loo_JsonOut = create oleobject
li_rc = loo_JsonOut.ConnectToNewObject("Chilkat.JsonObject")

loo_Json.UpdateString("payload.text","https://www.chilkatsoft.com/barcode_overview.asp")

//  Encode the same text at each level.
loo_Levels = create oleobject
li_rc = loo_Levels.ConnectToNewObject("Chilkat.JsonArray")

loo_Levels.Load("[~"L~",~"M~",~"Q~",~"H~"]")

for i = 0 to 3
    loo_Json.UpdateString("encoding.qr.errorCorrection",loo_Levels.StringAt(i))
    li_Success = loo_Fmt.QrCode("generate",loo_Json,loo_JsonOut)
    if li_Success = 0 then
        Write-Debug loo_Fmt.LastErrorText
        destroy loo_Fmt
        destroy loo_Json
        destroy loo_JsonOut
        destroy loo_Levels
        return
    end if

    Write-Debug "level " + loo_Levels.StringAt(i) + ": version " + string(loo_JsonOut.IntOf("symbols[0].selectedEncoding.version")) + ", " + string(loo_JsonOut.IntOf("symbols[0].dimensions.modulesWide")) + " modules wide"
next

//  The four symbols.  They hold the same text, and the higher the level, the larger the symbol:

//  

//  A symbol often has room left over.  boostErrorCorrection uses it: the level is raised
//  as far as the same version allows, so the symbol is no larger but is more robust.
loo_Json2 = create oleobject
li_rc = loo_Json2.ConnectToNewObject("Chilkat.JsonObject")

loo_Json2.UpdateString("payload.text","https://chilkatsoft.com")
loo_Json2.UpdateString("encoding.qr.errorCorrection","L")
li_Success = loo_Fmt.QrCode("generate",loo_Json2,loo_JsonOut)
if li_Success = 0 then
    Write-Debug loo_Fmt.LastErrorText
    destroy loo_Fmt
    destroy loo_Json
    destroy loo_JsonOut
    destroy loo_Levels
    destroy loo_Json2
    return
end if

Write-Debug "level L requested: version " + string(loo_JsonOut.IntOf("symbols[0].selectedEncoding.version")) + ", level " + loo_JsonOut.StringOf("symbols[0].selectedEncoding.errorCorrection")

loo_Json2.UpdateBool("encoding.qr.boostErrorCorrection",1)
li_Success = loo_Fmt.QrCode("generate",loo_Json2,loo_JsonOut)
if li_Success = 0 then
    Write-Debug loo_Fmt.LastErrorText
    destroy loo_Fmt
    destroy loo_Json
    destroy loo_JsonOut
    destroy loo_Levels
    destroy loo_Json2
    return
end if

Write-Debug "level L with boost: version " + string(loo_JsonOut.IntOf("symbols[0].selectedEncoding.version")) + ", level " + loo_JsonOut.StringOf("symbols[0].selectedEncoding.errorCorrection")

//  Level L, and level M reached by the boost.  The two symbols are the same size:

//  

//  Sample output:

//  level L: version 3, 29 modules wide
//  level M: version 4, 33 modules wide
//  level Q: version 5, 37 modules wide
//  level H: version 6, 41 modules wide
//  level L requested: version 2, level L
//  level L with boost: version 2, level M


destroy loo_Fmt
destroy loo_Json
destroy loo_JsonOut
destroy loo_Levels
destroy loo_Json2