Android NFC: I can't catch empty tag intent

Issue

Thank's to everyone who take the time to read this. Sorry for my bad english. I learn, I promise.

I'm working on an Android application which used NFC. I have a problem with empty tag. I can't catch the intent when I read an empty tag, it always launch the Android Activity to read ta tag, with the mention empty tag. For other tag with something write, I have no problem.

I search but I don't find something good. I think my problem is in the manifest.

So, I add this, of course:

<uses-permission android:name="android.permission.NFC" />

<uses-feature
    android:name="android.hardware.nfc"
    android:required="true" />

And in the activity I add, in first time

<intent-filter>
            <action android:name="android.nfc.action.TECH_DISCOVERED" />

            <data android:mimeType="text/plain" />
 </intent-filter>

 <meta-data
            android:name="android.nfc.action.TECH_DISCOVERED"
            android:resource="@xml/nfc" />

The xml/nfc.xml resource file contains the following technology filters:

<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2" >
    <tech-list>
        <tech>android.nfc.tech.IsoDep</tech>
        <tech>android.nfc.tech.NfcA</tech>
        <tech>android.nfc.tech.NfcB</tech>
        <tech>android.nfc.tech.NfcF</tech>
        <tech>android.nfc.tech.NfcV</tech>
        <tech>android.nfc.tech.Ndef</tech>
        <tech>android.nfc.tech.NdefFormatable</tech>
        <tech>android.nfc.tech.MifareClassic</tech>
        <tech>android.nfc.tech.MifareUltralight</tech>
    </tech-list>
</resources>

I read in some website that it may be important to add

<intent-filter>
            <action android:name="android.nfc.action.TAG_DISCOVERED" />

            <category android:name="android.intent.category.DEFAULT" />
</intent-filter>
<intent-filter>
            <action android:name="android.nfc.action.NDEF_DISCOVERED" />

            <category android:name="android.intent.category.DEFAULT" />

            <data android:mimeType="*/*" />
</intent-filter>

So I did.

But it didn't work.

I know I probably forgot something. But what?

Solution

Ok, I solved my problem! That was not the manifest but the java code.

In first time I read a tutorial about nfc and I use some part of the code. And there was some code that I had not adapted to the advice you gave me.

This is the old part of my code

IntentFilter[] filters = new IntentFilter[1];
filters[0] = new IntentFilter();
filters[0].addAction(NfcAdapter.ACTION_TECH_DISCOVERED);
try {
    filters[0].addDataType(MIME_TEXT_PLAIN);
} catch (MalformedMimeTypeException e) {
    Log.e("App","Wrong mime")
}
adapter.enableForegroundDispatch(activity, pendingIntent, filters, techList);

Wrong action, mime type. Many errors... I change for

final PendingIntent pendingIntent = PendingIntent.getActivity(activity.getApplicationContext(), 0, intent, 0);
adapter.enableForegroundDispatch(activity, pendingIntent, null, null);

And it works perfectly! I hope it can help someone like you helped me by your explanations.

Thank you again for your time!

Answered By - tatianag