DataFlex Requires Chilkat v11.7.0+

Generate a QR Code PNG in Memory

See more QR Code Examples

Demonstrates getting a QR code image without writing a file. With no output options the result is a PNG returned as base64 in outputs[0].base64 of the response. The example decodes it into a BinData, which holds the bytes of the PNG to send in an HTTP response, store in a database, attach to an email, or save. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Variant vJson
    Handle hoJson
    Handle hoFmt
    Variant vJsonOut
    Handle hoJsonOut
    Handle hoBdPng
    String sTemp1
    Integer iTemp1
    Integer iTemp2

    Move False To iSuccess

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

    Get Create (RefClass(cComChilkatJsonObject)) To hoJson
    If (Not(IsComObjectCreated(hoJson))) Begin
        Send CreateComObject of hoJson
    End
    Get ComUpdateString Of hoJson "payload.text" "https://www.chilkatsoft.com/" To iSuccess
    Get ComUpdateInt Of hoJson "render.moduleSize" 6 To iSuccess

    Get Create (RefClass(cComChilkatFormats)) To hoFmt
    If (Not(IsComObjectCreated(hoFmt))) Begin
        Send CreateComObject of hoFmt
    End
    Get Create (RefClass(cComChilkatJsonObject)) To hoJsonOut
    If (Not(IsComObjectCreated(hoJsonOut))) Begin
        Send CreateComObject of hoJsonOut
    End
    Get pvComObject of hoJson to vJson
    Get pvComObject of hoJsonOut to vJsonOut
    Get ComQrCode Of hoFmt "generate" vJson vJsonOut To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoFmt To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComStringOf Of hoJsonOut "outputs[0].format" To sTemp1
    Showln "format: " sTemp1
    Get ComStringOf Of hoJsonOut "outputs[0].mimeType" To sTemp1
    Showln "MIME type: " sTemp1
    Get ComIntOf Of hoJsonOut "outputs[0].width" To iTemp1
    Get ComIntOf Of hoJsonOut "outputs[0].height" To iTemp2
    Showln "image: " iTemp1 " x " iTemp2 " pixels"

    //  outputs[0].base64 is the PNG file, base64 encoded.
    Get Create (RefClass(cComChilkatBinData)) To hoBdPng
    If (Not(IsComObjectCreated(hoBdPng))) Begin
        Send CreateComObject of hoBdPng
    End
    Get ComStringOf Of hoJsonOut "outputs[0].base64" To sTemp1
    Get ComAppendEncoded Of hoBdPng sTemp1 "base64" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoBdPng To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComNumBytes Of hoBdPng To iTemp1
    Showln "PNG bytes: " iTemp1

    //  The BinData holds the image.  Here it is simply saved.
    Get ComWriteFile Of hoBdPng "qa_output/qr_in_memory.png" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoBdPng To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  The PNG held in bdPng:

    //  

    //  Sample output:

    //  format: png
    //  MIME type: image/png
    //  image: 222 x 222 pixels
    //  PNG bytes: 877


End_Procedure