Go 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. Go

    success := false

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

    json := chilkat.NewJsonObject()
    json.UpdateString("payload.text","https://www.chilkatsoft.com/")
    json.UpdateInt("render.moduleSize",6)

    fmt := chilkat.NewFormats()
    jsonOut := chilkat.NewJsonObject()
    success = fmt.QrCode("generate",json,jsonOut)
    if success == false {
        fmt.Println(fmt.LastErrorText())
        json.DisposeJsonObject()
        fmt.DisposeFormats()
        jsonOut.DisposeJsonObject()
        return
    }

    fmt.Println("format: ", *jsonOut.StringOf("outputs[0].format"))
    fmt.Println("MIME type: ", *jsonOut.StringOf("outputs[0].mimeType"))
    fmt.Println("image: ", jsonOut.IntOf("outputs[0].width"), " x ", jsonOut.IntOf("outputs[0].height"), " pixels")

    //  outputs[0].base64 is the PNG file, base64 encoded.
    bdPng := chilkat.NewBinData()
    success = bdPng.AppendEncoded(*jsonOut.StringOf("outputs[0].base64"),"base64")
    if success == false {
        fmt.Println(bdPng.LastErrorText())
        json.DisposeJsonObject()
        fmt.DisposeFormats()
        jsonOut.DisposeJsonObject()
        bdPng.DisposeBinData()
        return
    }

    fmt.Println("PNG bytes: ", bdPng.NumBytes())

    //  The BinData holds the image.  Here it is simply saved.
    success = bdPng.WriteFile("qa_output/qr_in_memory.png")
    if success == false {
        fmt.Println(bdPng.LastErrorText())
        json.DisposeJsonObject()
        fmt.DisposeFormats()
        jsonOut.DisposeJsonObject()
        bdPng.DisposeBinData()
        return
    }

    //  The PNG held in bdPng:

    //  

    //  Sample output:

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

    json.DisposeJsonObject()
    fmt.DisposeFormats()
    jsonOut.DisposeJsonObject()
    bdPng.DisposeBinData()