android NFC 使用示例

/* * Copyright 2011, The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.nfc.demo; import android.app.Activity; import android.app.AlertDialog; import android.app.PendingIntent; import android.content.DialogInterface; import android.content.Intent; import android.content.IntentFilter; import android.content.IntentFilter.MalformedMimeTypeException; import android.nfc.NdefMessage; import android.nfc.NdefRecord; import android.nfc.NfcAdapter; import android.nfc.Tag; import android.nfc.tech.Ndef; import android.nfc.tech.NdefFormatable; import android.os.Bundle; import android.os.Parcelable; import android.text.Editable; import android.text.TextWatcher; import android.util.Log; import android.view.View; import android.widget.EditText; import android.widget.Toast; import java.io.IOException; public class MainActivity extends Activity { private static final String TAG = "stickynotes"; // private boolean mResumed = false; private boolean mWriteMode = false; NfcAdapter mNfcAdapter; EditText mNote; EditText mNoteRead; PendingIntent mNfcPendingIntent; IntentFilter[] mWriteTagFilters; IntentFilter[] mNdefExchangeFilters; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mNfcAdapter = NfcAdapter.getDefaultAdapter(this); setContentView(R.layout.main); findViewById(R.id.write_tag).setOnClickListener(mTagWriter); findViewById(R.id.read_tag).setOnClickListener(mTagRead); mNote = ((EditText) findViewById(R.id.note)); mNote.addTextChangedListener(mTextWatcher); mNoteRead = ((EditText) findViewById(R.id.noteRead)); // Handle all of our received NFC intents in this activity. mNfcPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0); // Intent filters for reading a note from a tag or exchanging over p2p. IntentFilter ndefDetected = new IntentFilter( NfcAdapter.ACTION_NDEF_DISCOVERED); try { ndefDetected.addDataType("text/plain"); } catch (MalformedMimeTypeException e) { } mNdefExchangeFilters = new IntentFilter[] { ndefDetected }; // Intent filters for writing to a tag IntentFilter tagDetected = new IntentFilter( NfcAdapter.ACTION_TAG_DISCOVERED); mWriteTagFilters = new IntentFilter[] { tagDetected }; } @Override protected void onResume() { super.onResume(); // mResumed = true; // Sticky notes received from Android if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(getIntent().getAction())) { NdefMessage[] messages = getNdefMessages(getIntent()); byte[] payload = messages[0].getRecords()[0].getPayload(); setNoteBody(new String(payload)); setIntent(new Intent()); // Consume this intent. } enableNdefExchangeMode(); } @Override protected void onPause() { super.onPause(); // mResumed = false; mNfcAdapter.disableForegroundNdefPush(this); } @Override protected void onNewIntent(Intent intent) { // NDEF exchange mode if (!mWriteMode && NfcAdapter.ACTION_NDEF_DISCOVERED.equals(intent.getAction())) { NdefMessage[] msgs = getNdefMessages(intent); String body = new String(msgs[0].getRecords()[0].getPayload()); setNoteBody(body); } // Tag writing mode if (mWriteMode && NfcAdapter.ACTION_TAG_DISCOVERED.equals(intent.getAction())) { Tag detectedTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG); writeTag(getNoteAsNdef(), detectedTag); } } private TextWatcher mTextWatcher = new TextWatcher() { @Override public void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) { } @Override public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) { } @Override public void afterTextChanged(Editable arg0) { // if (mResumed) { // mNfcAdapter.enableForegroundNdefPush(MainActivity.this, getNoteAsNdef()); // } } }; private View.OnClickListener mTagWriter = new View.OnClickListener() { @Override public void onClick(View arg0) { // Write to a tag for as long as the dialog is shown. disableNdefExchangeMode(); enableTagWriteMode(); new AlertDialog.Builder(MainActivity.this).setTitle("Touch tag to write") .setOnCancelListener(new DialogInterface.OnCancelListener() { @Override public void onCancel(DialogInterface dialog) { disableTagWriteMode(); enableNdefExchangeMode(); } }).create().show(); } }; private View.OnClickListener mTagRead = new View.OnClickListener() { @Override public void onClick(View arg0) { // Write to a tag for as long as the dialog is shown. disableTagWriteMode(); enableNdefExchangeMode(); new AlertDialog.Builder(MainActivity.this).setTitle("Touch tag to read") .setOnCancelListener(new DialogInterface.OnCancelListener() { @Override public void onCancel(DialogInterface dialog) { disableTagWriteMode(); enableNdefExchangeMode(); } }).create().show(); } }; private void setNoteBody(String body) { Editable text = mNoteRead.getText(); text.clear(); text.append(body); } private NdefMessage getNoteAsNdef() { byte[] textBytes = mNote.getText().toString().getBytes(); NdefRecord textRecord = new NdefRecord(NdefRecord.TNF_MIME_MEDIA, "text/plain".getBytes(), new byte[] {}, textBytes); return new NdefMessage(new NdefRecord[] { textRecord }); } NdefMessage[] getNdefMessages(Intent intent) { // Parse the intent NdefMessage[] msgs = null; String action = intent.getAction(); if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(action) || NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) { Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES); if (rawMsgs != null) { msgs = new NdefMessage[rawMsgs.length]; for (int i = 0; i < rawMsgs.length; i++) { msgs[i] = (NdefMessage) rawMsgs[i]; } } else { // Unknown tag type byte[] empty = new byte[] {}; NdefRecord record = new NdefRecord(NdefRecord.TNF_UNKNOWN, empty, empty, empty); NdefMessage msg = new NdefMessage(new NdefRecord[] { record }); msgs = new NdefMessage[] { msg }; } } else { Log.d(TAG, "Unknown intent."); finish(); } return msgs; } private void enableNdefExchangeMode() { mNfcAdap