DataFlex Requires Chilkat v11.7.0+

QR Code Colors and Transparent Background

See more QR Code Examples

Demonstrates colored QR codes. render.foreground is the color of the dark modules and render.background the color behind them, each as #RRGGBB. Either can instead be an object with a color and an opacity from 0 to 1, and a background opacity of 0 gives a PNG with a transparent background to place over a page or a design. Readers need contrast: keep the modules clearly darker than whatever ends up behind them. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoFmt
    Variant vJsonOut
    Handle hoJsonOut
    Variant vJson
    Handle hoJson
    Variant vJson2
    Handle hoJson2
    String sTemp1
    Integer iTemp1

    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(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

    //  Dark blue modules on a pale yellow background.
    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 ComUpdateString Of hoJson "render.foreground" "#1B3A6B" To iSuccess
    Get ComUpdateString Of hoJson "render.background" "#FFF8DC" To iSuccess
    Get ComUpdateString Of hoJson "output.path" "qa_output/qr_blue.png" To iSuccess
    Get ComUpdateBool Of hoJson "output.overwrite" True To iSuccess
    Get ComUpdateString Of hoJson "output.return" "none" To iSuccess
    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].path" To sTemp1
    Get ComIntOf Of hoJsonOut "outputs[0].byteCount" To iTemp1
    Showln "colored: " sTemp1 ", " iTemp1 " bytes"

    //  The image written to qa_output/qr_blue.png:

    //  

    //  The same modules on a fully transparent background.
    Get Create (RefClass(cComChilkatJsonObject)) To hoJson2
    If (Not(IsComObjectCreated(hoJson2))) Begin
        Send CreateComObject of hoJson2
    End
    Get ComUpdateString Of hoJson2 "payload.text" "https://www.chilkatsoft.com/" To iSuccess
    Get ComUpdateInt Of hoJson2 "render.moduleSize" 6 To iSuccess
    Get ComUpdateString Of hoJson2 "render.foreground" "#1B3A6B" To iSuccess
    Get ComUpdateString Of hoJson2 "render.background.color" "#FFFFFF" To iSuccess
    Get ComUpdateNumber Of hoJson2 "render.background.opacity" "0" To iSuccess
    Get ComUpdateString Of hoJson2 "output.path" "qa_output/qr_transparent.png" To iSuccess
    Get ComUpdateBool Of hoJson2 "output.overwrite" True To iSuccess
    Get ComUpdateString Of hoJson2 "output.return" "none" To iSuccess
    Get pvComObject of hoJson2 to vJson2
    Get pvComObject of hoJsonOut to vJsonOut
    Get ComQrCode Of hoFmt "generate" vJson2 vJsonOut To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoFmt To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComStringOf Of hoJsonOut "outputs[0].path" To sTemp1
    Get ComIntOf Of hoJsonOut "outputs[0].byteCount" To iTemp1
    Showln "transparent: " sTemp1 ", " iTemp1 " bytes"

    //  qa_output/qr_transparent.png, placed here over a checkerboard and over a colored page
    //  to show that whatever is behind the image shows through:

    //  

    //  Sample output:

    //  colored: qa_output/qr_blue.png, 1345 bytes
    //  transparent: qa_output/qr_transparent.png, 1377 bytes


End_Procedure