Hi, I am developing an application to read and write data to an NFC tag. I have a problem reading data from an NFC tag. When I try to read the data, my application fails for the first time and again when scanning the tag for the second time the application reads the data. Please help me in this matter. Here is my code. Thanks in advance.
public class Read extends Activity { Tag detectedTag; TextView txtType,txtSize,txtWrite,txtRead; NfcAdapter nfcAdapter; IntentFilter[] readTagFilters; PendingIntent pendingIntent; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_CUSTOM_TITLE); setContentView(R.layout.read); getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.custom_title); nfcAdapter = NfcAdapter.getDefaultAdapter(); detectedTag =getIntent().getParcelableExtra(NfcAdapter.EXTRA_TAG); txtType = (TextView) findViewById(R.id.txtType); txtSize = (TextView) findViewById(R.id.txtsize); txtWrite = (TextView) findViewById(R.id.txtwrite); txtRead = (TextView) findViewById(R.id.txt_read); pendingIntent = PendingIntent.getActivity(getApplicationContext(), 0, new Intent(this,getClass()). addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0); IntentFilter tagDetected = new IntentFilter(NfcAdapter.ACTION_TAG_DISCOVERED); IntentFilter filter2 = new IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED); readTagFilters = new IntentFilter[]{tagDetected,filter2}; } protected void onNewIntent(Intent intent) { if(getIntent().getAction().equals(NfcAdapter.ACTION_TAG_DISCOVERED)){ detectedTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG); readFromTag(getIntent()); } } @Override protected void onResume() { super.onResume(); nfcAdapter.enableForegroundDispatch(this, pendingIntent, readTagFilters, null); } public void readFromTag(Intent intent){ Ndef ndef = Ndef.get(detectedTag); try{ ndef.connect(); txtType.setText(ndef.getType().toString()); txtSize.setText(String.valueOf(ndef.getMaxSize())); txtWrite.setText(ndef.isWritable() ? "True" : "False"); Parcelable[] messages = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES); if (messages != null) { NdefMessage[] ndefMessages = new NdefMessage[messages.length]; for (int i = 0; i < messages.length; i++) { ndefMessages[i] = (NdefMessage) messages[i]; } NdefRecord record = ndefMessages[0].getRecords()[0]; byte[] payload = record.getPayload(); String text = new String(payload); txtRead.setText(text); ndef.close(); } } catch (Exception e) { Toast.makeText(getApplicationContext(), "Cannot Read From Tag.", Toast.LENGTH_LONG).show(); } } }
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