读取使用NFC工具编写的NFC标签

Question

I followed this tutorial: https://www.codexpedia.com/android/android-nfc-read-and-write-example/ If I use I can read and write the tags, if I use when I try to read a NFC written with NFC tools, android starts trigger but not my app. It is possibile to read NFC tags written with other apps? thanks

Answer 1

There is a NFC service running in the background. When tag is detected it processes that event. It identifies the type of Tag and then creates an intent accordingly. There can be more than one application in Android device that are interested to process the tag. The tag dispatch system of the NFC Service decides the application to be launched.

In order to let NFC service know that your app is interested, your app should declare an intent filter with intent's action among the following: ACTION_NDEF_DISCOVERED, ACTION_TECH_DISCOVERED, ACTION_TAG_DISCOVERED.

Note that filtering for TECH_DISCOVERED intent needs an additional xml file that has one or more elements. All the listed techs in it should be supported by tag for a match. This file name should be specified in intent-filter for tech.

Refer to https://developer.android.com/guide/topics/connectivity/nfc/nfc#dispatching for complete details.