Use the barcode generator extension to generate a full range of barcodes (Codabar, Code 39, Code 128, EAN-8, EAN-13, ITF, PDF417, QR code, UPC-A). You can set the bar color and the background color and save the resulting image to your SD card.
Call the GenerateBarcode block with the following inputs:
text = the content of the barcode
format = choose one of the format specifications (CODABAR, CODE_39, CODE_128, EAN_8, EAN_13, ITF, PDF_417, QR_CODE, UPC_A) and provide it as a string
width and height = size in pixels (note that the generator may add a quiet zone around the barcode)
The Color and BackgroundColor blocks use the App Inventor color component.
The FileName is the relative path on your SD card, for example "barcode.png" or "/qr/barcode.png".
The example shows how the Barcode Generator can be used together with the ESC/POS Simple Converter. The user input consists of a text field for the content, a spinner using the format specifications as list of elements, and two numerical text fields for the size. A button generates the barcode and saves it to the SD card. It is then displayed on the screen and printed using a bluetooth thermal printer.
If you have questions or want to purchase the Barcode Generator extension, please contact me via the contact form!