如果不遵守我的条件，如何停止读取 NFC？

Question

I want to stop the NFC reading process and display a textView in case of the my if condition is not respected. If I do not have the 'S', I want the process of reading to be stopped my current code doesn't stop the process.

 private void readFromIntent(Intent intent) {
        String action = intent.getAction();
        if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(action)
                || NfcAdapter.ACTION_TECH_DISCOVERED.equals(action)
                || NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) {
            Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
            NdefMessage[] msgs = null;
            if (rawMsgs != null) {
                msgs = new NdefMessage[rawMsgs.length];
                for (int i = 0; i < rawMsgs.length; i++) {
                    msgs[i] = (NdefMessage) rawMsgs[i];
                }
            }
            buildTagViews(msgs);
        }
    }
    private void buildTagViews(NdefMessage[] msgs) {
        if (msgs == null || msgs.length == 0) return;

        String text = "";
//        String tagId = new String(msgs[0].getRecords()[0].getType());
        byte[] payload = msgs[0].getRecords()[0].getPayload();
        String textEncoding = ((payload[0] & 128) == 0) ? "UTF-8" : "UTF-16"; // Get the Text Encoding
        int languageCodeLength = payload[0] & 0063; // Get the Language Code, e.g. "en"
        // String languageCode = new String(payload, 1, languageCodeLength, "US-ASCII");

        try {
            // Get the Text

            text = new String(payload, languageCodeLength + 1, payload.length - languageCodeLength - 1, textEncoding);
        } catch (UnsupportedEncodingException e) {
            Log.e("UnsupportedEncoding", e.toString());
        }


        if (text.charAt(0)!='S'){
            Alerte.setVisibility(View.GONE);
        }
else{
            Alerte.setVisibility(View.VISIBLE);
        }

Answer 1

Your probably using the Foreground dispatch mechanism to receive the NFC data to your running app though you don't show this code.

So to stop receiving NFC Intent messages just call disableForegroundDispatch on the nfcAdaptor https://developer.android.com/reference/android/nfc/NfcAdapter#disableForegroundDispatch(android.app.Activity)