如何从 NFC 标签中删除 NDEF 消息？

Question

I am working on NFC. I am able to write message on tag. Everything is working fine but when I try to erase the tag, it does not work and I don't know why. Here is my code:

Tag mytag = getIntent().getParcelableExtra(NfcAdapter.EXTRA_TAG);
NdefFormatable formatable = NdefFormatable.get(mytag);

if (formatable != null) {
        formatable.connect();
        formatable.format(methodGetMsg());
        formatable.close();
}

I'm always getting formatable value null .

Answer 1

As your tag already lists the android.nfc.tech.Ndef technology, it is already prepared to store an NDEF message and does not need further formatting. You can simply overwrite (given that the tag is not read-only) any existing NDEF message by using the writeNdefMessage() method of the Ndef object. Eg to "format" the tag to an empty NDEF message, you could do something like:

Ndef ndefTag = Ndef.get(tag);
ndefTag.writeNdefMessage(new NdefMessage(new NdefRecord(NdefRecord.TNF_EMPTY, null, null, null)));

Taken from here