我必须在2个活动之间交换数据，第一个是管理数据，第二个是用标签管理通信NFC（总是在前台）。 第一个Activity使用startActivityForResult启动第二个Activity。 我实施了BroadCastReceiver来管理两个活动之间的双向交换。 startActivityForResult已经很好地启动了，我在DroidReader中获得了很好的数据，DroidReader返回给MainActivity的数据还可以。但是当我重新尝试MainActivity的context.sendBroadcast（i）以再次向DroidReader发送信息时，我从未对DroidReader方面有所了解。 TX为您提供了很多帮助。
这是MainActivity
public class MainActivity extends Activity {
private TextView mTextView;
public static final String TAG = "MainDemo";
final static int REQUEST_CODE = 1;
private Receiver mReceiver;
private class Receiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals("SOMEACTION")) {
handleMessage(context, intent);
Log.i(TAG, "onReceive");
}else
Log.i(TAG, "noT onReceive");
}
private void handleMessage(Context context, Intent intent) {
byte[] retour = intent.getByteArrayExtra("Return");
Log.i(TAG, "byte array : "+byteArrayToSHex(retour));
Intent i = new Intent();
i.setAction("android.intent.action.MAIN");
i.putExtras(intent);
Log.i(TAG, "passage dans handleMessage");
// context.sendOrderedBroadcast(i, null);
context.sendBroadcast(i);
// Intent i = new Intent("android.intent.action.AndroidReader").putExtra("APDUReturn", retour);
// this.sendBroadcast(i);
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mReceiver = new Receiver();
IntentFilter filter = new IntentFilter();
filter.addAction("SOMEACTION");
this.registerReceiver(mReceiver, filter);
mTextView = (TextView) findViewById(R.id.textView_explanation);
Button start = (Button) findViewById(R.id.start_button);
start.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(MainActivity.this, AndroidReader.class);
byte[] data1 = {0x00, (byte) 0xA4};
APDUBundle apduBundle = new APDUBundle(data1, true/*, intent*/);
intent.putExtra("data", data1);//.putCharSequenceArrayListExtra(("paramFirst", seReq);
intent.putExtra("case4", true);
intent.setAction("android.intent.action.MAIN");
Log.i(TAG, "MainActivity:Oncreate");
startActivityForResult(intent, REQUEST_CODE);
}
});
public void onResume() {
super.onResume();
registerReceiver(myBroadcastReceiver, intentFilter);
}
public void onPause() {
super.onPause();
unregisterReceiver(myBroadcastReceiver);
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REQUEST_CODE){
if(resultCode == RESULT_OK){
byte[] result=data.getByteArrayExtra("Return");
// APDUBundle apduBundle = getIntent().getParcelableExtra("APDUBundle");
Toast.makeText(getApplicationContext(), /*byteArrayToSHex(apduBundle.getAPDU())*/byteArrayToSHex(result), Toast.LENGTH_SHORT).show();
}
if (resultCode == RESULT_CANCELED) {
//Write your code if there's no result
Toast.makeText(getApplicationContext(), "Nothing Returned!", Toast.LENGTH_SHORT).show();
}
}
}
@Override
protected void onDestroy(){
super.onDestroy();
if(mReceiver!=null)
this.unregisterReceiver(mReceiver);
}
}
这是DroidReader
public class AndroidReader extends Activity {
public static final String MIME_TEXT_PLAIN = "text/plain";
public static final String TAG = "NfcDemo";
private TextView mTextViewNFC;
private NfcAdapter mNfcAdapter;
byte[] dataIntent = null;
boolean case4Intent = false;
Tag mTag = null ;
/**
* ATTENTION: This was auto-generated to implement the App Indexing API.
* See https://g.co/AppIndexing/AndroidStudio for more information.
*/
// private GoogleApiClient client;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_nfc);
mTextViewNFC = (TextView) findViewById(R.id.textView_explanationNFC);
mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
if (mNfcAdapter == null) {
// Stop here, we definitely need NFC
Toast.makeText(this, "This device doesn't support NFC.", Toast.LENGTH_LONG).show();
finish();
return;
}
if (!mNfcAdapter.isEnabled()) {
mTextViewNFC.setText("NFC is disabled.");
} else {
mTextViewNFC.setText(R.string.explanation);
}
handleIntent(getIntent());
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
// client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
}
@Override
protected void onResume() {
super.onResume();
/**
* It's important, that the activity is in the foreground (resumed). Otherwise
* an IllegalStateException is thrown.
*/
setupForegroundDispatch(this, mNfcAdapter);
}
@Override
protected void onPause() {
/**
* Call this before onPause, otherwise an IllegalArgumentException is thrown as well.
*/
stopForegroundDispatch(this, mNfcAdapter);
super.onPause();
}
@Override
protected void onNewIntent(Intent intent) {
/**
* This method gets called, when a new Intent gets associated with the current activity instance.
* Instead of creating a new activity, onNewIntent will be called. For more information have a look
* at the documentation.
*
* In our case this method gets called, when the user attaches a Tag to the device.
*/
byte[] retour = handleIntent(intent);
Log.i(TAG, "Return :"+byteArrayToSHex(retour));
Intent i = new Intent("SOMEACTION").putExtra("Return", retour);
this.sendBroadcast(i);
}
private byte[] handleIntent(Intent intent) {
// TODO: handle Intent
String action = intent.getAction();
Log.i(TAG, "handleIntent :"+action);
byte[] res = {};
if ("android.intent.action.MAIN".equals(action)) {
dataIntent = getIntent().getByteArrayExtra("data");
case4Intent = getIntent().getBooleanExtra("case4", true);
Log.i(TAG, "value dataIntent:"+dataIntent);
Log.i(TAG, "value case4Intent:"+case4Intent);
// Log.i(TAG, "value getIntent:"+apduBundle.getIntent());
res = {0x00};
}
return res;
}
/**
* @param activity The corresponding {@link Activity} requesting the foreground dispatch.
* @param adapter The {@link NfcAdapter} used for the foreground dispatch.
*/
public static void setupForegroundDispatch(final Activity activity, NfcAdapter adapter) {
final Intent intent = new Intent(activity.getApplicationContext(), activity.getClass());
intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
final PendingIntent pendingIntent = PendingIntent.getActivity(activity, 0, intent, 0);
adapter.enableForegroundDispatch(activity, pendingIntent, null, null);
}
/**
* @param activity The corresponding {@link BaseActivity} requesting to stop the foreground dispatch.
* @param adapter The {@link NfcAdapter} used for the foreground dispatch.
*/
public static void stopForegroundDispatch(final Activity activity, NfcAdapter adapter) {
adapter.disableForegroundDispatch(activity);
}
}