问题
I developed a BarcodeScanner app with ZXING library. for that I downloaded the complete library and added it to my proj and called an Intent with URI:"com.myproject.vinscan.client.android.SCAN". but later I found that, instead of downloading and including all packages of ZXING into our proj, we can just use the URI for Inetnt as "com.google.zxing.client.android.SCAN". My doubt is, how is it working without the libraries. It is working even in offline mode(without WIFI/GPRS). are the libraries included in the android SDK itself?
回答1:
If you are accessing it via the intent, as com.google.zxing.client.android.SCAN it needs the Barcode Scanner application to be installed on the client. (Reference)
If it isn't installed, it redirects to the website and prompts the user to download. So strictly speaking, the user will have to be connected to the internet atleast once, in order to download the Barcode Scanner application (if he doesn't already have it)
Alternately
If you were to add a reference to the ZXing core library, into your project, you will be able to access it without having to direct the user out, to download Barcode Scanner.
来源：https://stackoverflow.com/questions/13005259/how-does-com-google-zxing-client-android-scan-work-in-android