android NFC开发实例
对于Android 4.0 SDK中提供的Beam例子，对于NFC开发来说的确是一个不错的模板。对于了解NFC的NDEF消息处理过程不妨看下面的代码。
public class Beam extends Activity implements CreateNdefMessageCallback, OnNdefPushCompleteCallback { NfcAdapter mNfcAdapter; TextView mInfoText; private static final int MESSAGE_SENT = 1; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mInfoText = (TextView) findViewById(R.id.textView); mNfcAdapter = NfcAdapter.getDefaultAdapter(this); //实例化NFC设备 if (mNfcAdapter == null) { mInfoText = (TextView) findViewById(R.id.textView); mInfoText.setText("NFC is not available on this device."); } mNfcAdapter.setNdefPushMessageCallback(this, this); //注册NDEF回调消息 mNfcAdapter.setOnNdefPushCompleteCallback(this, this); } @Override public NdefMessage createNdefMessage(NfcEvent event) { Time time = new Time(); time.setToNow(); String text = ("Beam me up!\n\n" + "Beam Time: " + time.format("%H:%M:%S")); NdefMessage msg = new NdefMessage( new NdefRecord[] { createMimeRecord( "application/com.example.android.beam", text.getBytes()) }); return msg; } @Override public void onNdefPushComplete(NfcEvent arg0) { // A handler is needed to send messages to the activity when this // callback occurs, because it happens from a binder thread mHandler.obtainMessage(MESSAGE_SENT).sendToTarget(); } private final Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { switch (msg.what) { case MESSAGE_SENT: Toast.makeText(getApplicationContext(), "Message sent!", Toast.LENGTH_LONG).show(); break; } } }; @Override public void onResume() { super.onResume(); if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(getIntent().getAction())) { processIntent(getIntent()); } } @Override public void onNewIntent(Intent intent) { // onResume gets called after this to handle the intent setIntent(intent); } /** * Parses the NDEF Message from the intent and prints to the TextView */ void processIntent(Intent intent) { Parcelable[] rawMsgs = intent.getParcelableArrayExtra( NfcAdapter.EXTRA_NDEF_MESSAGES); // only one message sent during the beam NdefMessage msg = (NdefMessage) rawMsgs[0]; // record 0 contains the MIME type, record 1 is the AAR, if present mInfoText.setText(new String(msg.getRecords()[0].getPayload())); } /** * Creates a custom MIME type encapsulated in an NDEF record * * @param mimeType */ public NdefRecord createMimeRecord(String mimeType, byte[] payload) { byte[] mimeBytes = mimeType.getBytes(Charset.forName("US-ASCII")); NdefRecord mimeRecord = new NdefRecord( NdefRecord.TNF_MIME_MEDIA, mimeBytes, new byte[0], payload); return mimeRecord; } @Override public boolean onCreateOptionsMenu(Menu menu) { // If NFC is not available, we won't be needing this menu if (mNfcAdapter == null) { return super.onCreateOptionsMenu(menu); } MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.options, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.menu_settings: Intent intent = new Intent(Settings.ACTION_NFCSHARING_SETTINGS); startActivity(intent); return true; default: return super.onOptionsItemSelected(item); } } }
jopen 
openkk