I am trying to create an application using NFC and I just want to try and read an NFC tag and get the text message from the tag and place it into a TextView. I have code for it already, but nothing happens when I try to pair the phone with an NFC tag.
Here is my code and could someone please look at it and see what I am doing wrong and what needs to be done to fix the issue please:
Button measurementsDataButton;
NfcAdapter myNfcAdapter;
PendingIntent myPendingIntent;
IntentFilter ndef;
IntentFilter[] filters;
String[][] techLists;
int mCount;
TextView mText;
String payload;
byte payloadHeader;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_nfc_scanner);
final ActionBar actionBar = getActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
mText = (TextView) findViewById(R.id.flowTextView1);
measurementsDataButton = (Button) findViewById(R.id.measurementsButton1);
measurementsDataButton.setOnClickListener(this);
myNfcAdapter = NfcAdapter.getDefaultAdapter(this);
myPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
ndef = new IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED);
filters = new IntentFilter[] {ndef, };
techLists = new String[][] {new String[] {Ndef.class.getName()}, new String[] {NdefFormatable.class.getName()}};
}
@Override
public void onPause() {
super.onPause();
myNfcAdapter.disableForegroundDispatch(this);
}
@Override
public void onResume() {
super.onResume();
if(myNfcAdapter != null) {
myNfcAdapter.enableForegroundDispatch(this, myPendingIntent, filters, techLists);
}
}
@Override
public void onNewIntent(Intent intent) {
if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(getIntent()))
{
NdefMessage [] messages = getNdefMessages(getIntent());
for(int i = 0; i<messages.length; i++)
{
for(int j = 0; j<messages[0].getRecords().length; j++)
{
NdefRecord record = messages[i].getRecords()[j];
payload = new String(record.getPayload(), 1, record.getPayload().length-1, Charset.forName("UTF-8"));
mText.setText(payload);
payloadHeader = record.getPayload()[0];
}
}
}
}
NdefMessage[] getNdefMessages(Intent intent) {
// TODO Auto-generated method stub
NdefMessage[] message = null;
if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(intent.getAction())) {
Parcelable[] rawMessages = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
if(rawMessages != null) {
message = new NdefMessage[rawMessages.length];
for(int i = 0; i < rawMessages.length; i++) {
message[i] = (NdefMessage) rawMessages[i];
}
}
else {
byte[] empty = new byte[] {};
NdefRecord record = new NdefRecord (NdefRecord.TNF_UNKNOWN, empty, empty, empty);
NdefMessage msg = new NdefMessage (new NdefRecord[] {record});
message = new NdefMessage[] {msg};
}
}
else {
Log.d("", "Unknown intent.");
finish();
}
return message;
}
example of code for send-receive NDEF TAG:
public class MainActivity extends AppCompatActivity implements NfcAdapter.CreateNdefMessageCallback {
private NfcAdapter mNfcAdapter;
TextView tv;
private PendingIntent mPendingIntent;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = (TextView) findViewById(R.id.textViewReceivedMessage);
NfcManager nfcManager = (NfcManager) getSystemService(NFC_SERVICE);
mNfcAdapter = nfcManager.getDefaultAdapter();
mPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass())
.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
}
private static NdefMessage getTestMessage() {
byte[] mimeBytes = "application/com.android.cts.verifier.nfc"
.getBytes(Charset.forName("US-ASCII"));
byte[] id = new byte[] {1, 3, 3, 7};
byte[] payload = "CTS Verifier NDEF Push Tag".getBytes(Charset.forName("US-ASCII"));
return new NdefMessage(new NdefRecord[] {
new NdefRecord(NdefRecord.TNF_MIME_MEDIA, mimeBytes, id, payload)
});
}
@Override
protected void onResume() {
super.onResume();
mNfcAdapter.enableForegroundDispatch(this, mPendingIntent, null, null);
mNfcAdapter.setNdefPushMessageCallback(this, this);
}
// sending message
@Override
public NdefMessage createNdefMessage(NfcEvent event) {
return getTestMessage();
}
private NdefMessage[] getNdefMessages(Intent intent) {
Parcelable[] rawMessages = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
if (rawMessages != null) {
NdefMessage[] messages = new NdefMessage[rawMessages.length];
for (int i = 0; i < messages.length; i++) {
messages[i] = (NdefMessage) rawMessages[i];
}
return messages;
} else {
return null;
}
}
static String displayByteArray(byte[] bytes) {
String res="";
StringBuilder builder = new StringBuilder().append("[");
for (int i = 0; i < bytes.length; i++) {
res+=(char)bytes[i];
}
return res;
}
// displaying message
@Override
protected void onNewIntent(Intent intent) {
super.onNewIntent(intent);
NdefMessage[] messages = getNdefMessages(intent);
tv.setText(displayByteArray(messages[0].toByteArray()));
}
}