This project deploys an Azure Function on .NET Core 2.0. The function renders renders barcodes in various symbologies/formats and sizes.
This project depends on:
- ZXing licened under Apache v2.0.
- SixLabors ImageSharp licensed under Apache v2.0.
Available querystring arguments are:
| Argument | Description |
|---|---|
| v | The value you wish to encode as a barcode. |
| sym | The barcode symbology (format). Default is CODE_128. Must be one of the enum types defined by ZXing.BarcodeFormat. As of this writing, those types are: AZTEC, CODABAR, CODE_39, CODE_93, CODE_128, DATA_MATRIX, EAN_8, EAN_13, ITF, MAXICODE, PDF_417, QR_CODE, RSS_14, RSS_EXPANDED, UPC_A, UPC_E, All_1D, UPC_EAN_EXTENSION, MSI, PLESSEY, IMB |
| fmt | The output file format. Default: png. Options are 'png' and 'svg'. Height and width are irrelevant for SVG. Not sure about margin. |
| h | The height, in pixels, of the rendered barcode. Default: 40 pixels. For QR Code, there are certain jump-points between sizes that will cause a change in the outputted image size. Each Matrix code type has symmetrical representation requirements. It will always jump to an even number that is a multiple of the codeword size. |
| w | The width, in pixels, of the rendered barcode. Default: 0, which means 'unset' For 1D barcodes (like Code 128), leave unset to let the rendering engine decide. |
| m | Margins, in pixels. Default: 0. For 1D barcodes, this modifies the left and right margins. Top and bottom are untouched. |
Encode a Code 128 barcode with "Hello World" as the value. Output to PNG.
/api/barcode?v=Hello%20World
Encode a QR Code barcode with "Hello World" as the value, sized 200x200 pixels. Output to PNG.
/api/barcode?v=Hello%20World&sym=QR_CODE&h=200&w=200
Encode the same QR Code, output to SVG.
/api/barcode?v=Hello%20World&sym=QR_CODE&fmt=svg
This service cannot render the text of the value below the barcode.
This is a limitation of the Azure Functions platform, which does not allow use of routines that access the GDI graphics interface.
GDI is needed for font rendering. System.Drawing routines for rendering fonts are not available.
There's probably a workaround for this for the properly motivated developer.
PNG generally produces the smallest file sizes for barcodes compared to JPEG, GIF and BMP.
SVGs scale up infinitely without blurring, but the file size (an XML document) tends to be larger than PNG.