Client wants a button on the mobile web app that launches a QR code scan (with camera on iPad) then returns to the mobile web app with the QR code info. Wondering how best to achieve this and/or if it's even possible. Thanks!
Yes, see the zxing: URL format here.
Not really possible, sorry.
The closest you can get is some apps have a URL scheme (redlaser://, for example) that you could provide a link to. There's no way of detecting that they've got the app installed, though.
The best thing would be to use a bluetooth barcode scanner. Something like Socket scan , CX2864-1336 would work for well for this. I've seen it used with an ipad to manage inventory.
Seems like that would require two separate native applications. Both using URL schemes to jump to the other and pass information. If you have a web app and check for a QR code scanner's URL scheme it's totally possible for your web app to launch a QR code scan but passing data back would require a native app. Oh, and I'm not sure if there are any QR code apps with a scheme.
来源：https://stackoverflow.com/questions/11195178/is-it-possible-to-launch-a-qr-code-scan-from-a-mobile-web-app-running-on-ipad