Question

I have a question about the android NFC.

I have already done the function about read and write, but still have one problem.

I wrote the AAR in my tag, after first sensing, it can launch my application.

Second time sensing (my application is launched), I can read the data from NFC tag.

Is it possible just sensing once that can launch my application and get the data from tag?

Answer 1

In AndroidManifest –

  <activity
        android:name=".TagDiscoverer"
        android:alwaysRetainTaskState="true"
        android:label="@string/app_name"
        android:launchMode="singleInstance"
        android:screenOrientation="nosensor" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
        <intent-filter>
            <action android:name="android.nfc.action.NDEF_DISCOVERED" />
            <action android:name="android.nfc.action.TECH_DISCOVERED" />
            <action android:name="android.nfc.action.TAG_DISCOVERED" />

            <category android:name="android.intent.category.DEFAULT" />

            <data android:mimeType="text/plain" />
        </intent-filter>

        <meta-data
            android:name="android.nfc.action.TECH_DISCOVERED"/>
    </activity>

you should initiate the NFC adopter in OnCreate()..

     /**
      * Initiates the NFC adapter
     */
  private void initNfcAdapter() {
    nfcAdapter = NfcAdapter.getDefaultAdapter(this);
    mPendingIntent = PendingIntent.getActivity(this, 0,
        new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
   }

Now in OnResume() …

  @Override
  protected void onResume() {
  super.onResume();
  if (nfcAdapter != null) {
    nfcAdapter.enableForegroundDispatch(this, mPendingIntent, null, null);
  }
 }