In the beginning of App Inventor (version 1) using the activitystarter to generate a barcode was impossible.
There was only one ‘extras’ field but to generate a barcode you needed more.
I tested it and it works! Not only QR barcodes but also EAN13, Aztec, Code39, Code128 and many more!
I have made an example for you to test. All the barcodes that I have tested and that worked, are shown in the ‘TestedAndAcceptedBarcodeFormats’ block.
ZXing_Barcode_Generator.aia (4.2 KB)