NFC技术：使用Android Beam技术传输文本（一）

//实现两部Android手机文本传输
//4.0以上
//方法：将两部安卓手机背对背，一部手机输入文本，点击屏幕发送，另一部接收显示

public class MainActivity extends Activity implements
        CreateNdefMessageCallback, OnNdefPushCompleteCallback {

    private NfcAdapter mnfcAdapter;
    private EditText mBeamText;
    private PendingIntent mPendingIntent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fragment_main);
        mBeamText = (EditText) findViewById(R.id.editText1);
        mnfcAdapter = mnfcAdapter.getDefaultAdapter(this);
        mPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this,
                getClass()), 0);

        // 指定要传输文本的回调
        mnfcAdapter.setNdefPushMessageCallback(this, this);
        // 传输完成调用
        mnfcAdapter.setOnNdefPushCompleteCallback(this, this);
    }

    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
        if (mnfcAdapter != null) {
            mnfcAdapter.enableForegroundDispatch(this, mPendingIntent, null,
                    null);
        }
    }

    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        if (mnfcAdapter != null) {
            mnfcAdapter.disableForegroundDispatch(this);
        }
    }

    // 显示接收到的数据
    void processIntent(Intent intent) {

        Parcelable[] rawMsgs = intent
                .getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
        NdefMessage message = (NdefMessage) rawMsgs[0];
        String text = TextRecord.parse(message.getRecords()[0]).getText();
        Toast.makeText(this, text, 0).show();
    }

    @Override
    protected void onNewIntent(Intent intent) {
        // TODO Auto-generated method stub
        // super.onNewIntent(intent);
        processIntent(intent);
    }

    @Override
    public void onNdefPushComplete(NfcEvent event) {
        // TODO Auto-generated method stub
        Log.i("----->>", "完成");
    }

    @Override
    public NdefMessage createNdefMessage(NfcEvent event) {
        // TODO Auto-generated method stub

        String text = mBeamText.getText().toString().trim();
        if ("".equals(text)) {
            text = "默认文本";
            // 当手机靠近另一部手机，使它自动打开计算器
            // NdefMessage ndefMessage = new NdefMessage(
            // new NdefRecord[] { NdefRecord
            // .createApplicationRecord("com.android.calculator2") });
            //

            NdefMessage ndefMessage = new NdefMessage(
                    new NdefRecord[] { creatTextRecord(text) });
            return ndefMessage;
        }

        return null;
    }

    public NdefRecord creatTextRecord(String text) {

        byte[] langBytes = Locale.CHINA.getLanguage().getBytes(
                Charset.forName("US-ASCII"));
        Charset utfEncoding = Charset.forName("UTF-8");
        byte[] textBytes = text.getBytes(utfEncoding);
        int utfBit = 0;
        char status = (char) (utfBit + langBytes.length);
        byte[] data = new byte[1 + langBytes.length + textBytes.length];
        data[0] = (byte) status;
        System.arraycopy(langBytes, 0, data, 1, langBytes.length);
        System.arraycopy(textBytes, 0, data, 1 + langBytes.length,
                textBytes.length);

        NdefRecord ndefRecord = new NdefRecord(NdefRecord.TNF_WELL_KNOWN,
                NdefRecord.RTD_TEXT, new byte[0], data);
        return ndefRecord;

    }

}