android-Advanced NFC

There are cases, however, when you scan a tag that does not contain NDEF data or when the NDEF data could not be mapped to a MIME type or URI. In these cases, you need to open
communication directly with the tag and read and write to it with your own protocol (in raw bytes).

android.nfc.tech

package

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》The following example shows how to work with a MIFARE Ultralight tag.

package com.example.android.nfc;

import android.nfc.Tag;
import android.nfc.tech.MifareUltralight;
import android.util.Log;
import java.io.IOException;
import java.nio.charset.Charset;

public class MifareUltralightTagTester {

private static final String TAG = MifareUltralightTagTester.class.getSimpleName();

public void writeTag(Tag tag, String tagText) {
MifareUltralight ultralight = MifareUltralight.get(tag);
try {
ultralight.connect();
ultralight.writePage(4, "abcd".getBytes(Charset.forName("US-ASCII")));
ultralight.writePage(5, "efgh".getBytes(Charset.forName("US-ASCII")));
ultralight.writePage(6, "ijkl".getBytes(Charset.forName("US-ASCII")));
ultralight.writePage(7, "mnop".getBytes(Charset.forName("US-ASCII")));
} catch (IOException e) {
Log.e(TAG, "IOException while closing MifareUltralight...", e);
} finally {
try {
ultralight.close();
} catch (IOException e) {
Log.e(TAG, "IOException while closing MifareUltralight...", e);
}
}
}

public String readTag(Tag tag) {
MifareUltralight mifare = MifareUltralight.get(tag);
try {
mifare.connect();
byte[] payload = mifare.readPages(4);
return new String(payload, Charset.forName("US-ASCII"));
} catch (IOException e) {
Log.e(TAG, "IOException while writing MifareUltralight
message...", e);
} finally {
if (mifare != null) {
try {
mifare.close();
}
catch (IOException e) {
Log.e(TAG, "Error closing tag...", e);
}
}
}
return null;
}
}

》 Override the following activity lifecycle callbacks and add logic to enable and disable the foreground dispatch when the activity loses ([code]onPause()

) and regains (

onResume()

) focus.

, java.lang.String[][])]enableForegroundDispatch()

must be called from the main thread and only when the activity is in the foreground (calling in

onResume()

guarantees this). You also need to implement the

onNewIntent

callback to process the data from the scanned NFC tag.[/code]

public void onPause() {
super.onPause();
mAdapter.disableForegroundDispatch(this);
}

public void onResume() {
super.onResume();
mAdapter.enableForegroundDispatch(this, pendingIntent, intentFiltersArray, techListsArray);
}

public void onNewIntent(Intent intent) {
Tag tagFromIntent = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
//do something with tagFromIntent
}