Reputation: 31
I developed an application Android that detect NFC card then it open IsoDep connection with it to send APDU and get response. When application detect the NFC card it open a work session, I created a thread
that every 500 ms
check the isoDep connection, if connection was lost application close the work session (stop pooling , delete card data ...).
My application is device owner and is locked and it contain only one activity that start a webview to turn html code for user interfaces.
In The MainActivity, I stop the pooling in the onPause() before the super.onPause() and I restart it in the onResume() after the super.onResume().
Also I always call NfcAdapter.enableReaderMode()
in onResume() and NfcAdapter.disableReaderMode
in onPause().
//enable nfc dispatch
Bundle options = new Bundle();
options.putInt(NfcAdapter.EXTRA_READER_PRESENCE_CHECK_DELAY, 50);
NfcManager manager = (NfcManager) activity.
getApplicationContext().getSystemService(Context.NFC_SERVICE);
if(manager == null) {
return;
}
NfcAdapter nfcAdapter = manager.getDefaultAdapter();
if(nfcAdapter == null) {
return;
}
try {
nfcAdapter.enableReaderMode(activity,
new NfcAdapter.ReaderCallback() {
@Override
public void onTagDiscovered(final Tag tag) {
cardDetected(tag);
}
},
NfcAdapter.FLAG_READER_NFC_A | NfcAdapter.FLAG_READER_SKIP_NDEF_CHECK |
NfcAdapter.FLAG_READER_NO_PLATFORM_SOUNDS,
options);
} catch (Exception e) {
}
//disable nfc dispatch
NfcManager manager = (NfcManager)activity.getApplicationContext().getSystemService(Context.NFC_SERVICE);
if(manager == null) {
return;
}
NfcAdapter nfcAdapter = manager.getDefaultAdapter();
if(nfcAdapter == null) {
return;
}
try {
nfcAdapter.disableReaderMode(activity);
} catch (Exception e) {
}
I use Samsung Xcover4 Android 8 to test the application. And my problem is sometime when the onResume is called I see in the logcat a DeadObjectException :
E/NFC: NFC service dead - attempting to recover
android.os.DeadObjectException
at android.os.BinderProxy.transactNative(Native Method)
at android.os.BinderProxy.transact(Binder.java:777)
at android.nfc.INfcAdapter$Stub$Proxy.setAppCallback(INfcAdapter.java:1026)
at android.nfc.NfcActivityManager.requestNfcServiceCallback(NfcActivityMan ager.java:494)
at android.nfc.NfcActivityManager.onActivityResumed(NfcActivityManager.java:674)
at android.app.Application.dispatchActivityResumed(Application.java:240)
at android.app.Activity.onResume(Activity.java:1369)
at android.support.v4.app.FragmentActivity.onResume(FragmentActivity.java:514)
at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1363)
at android.app.Activity.performResume(Activity.java:7432)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3780)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3845)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1773)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:7000)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:441)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)
When it happen card is never detected and I have to restart NFC or application to be able to detect card.
Upvotes: 3
Views: 723