Formatting a Mifare Ultralight C to NDEF

问题

I want to format a Mifare Ultralight C to handle NDEF messages. I have written the code below and it works just fine with the Mifare Classic 1K chips but it gets an IOExeption when i try and connect to the Ultralight C chip.

NdefFormatable format = NdefFormatable.get(tag)

    if(format != null){
        try {
            format.connect();
            format.format(new NdefMessage(new NdefRecord(NdefRecord.TNF_EMPTY, null, null, null)));
            format.close();
            Toast.makeText(getApplicationContext(), "Tag formated.",    Toast.LENGTH_LONG).show();
        }catch (IOException e) {
            // TODO Auto-generated catch block
            Toast.makeText(getApplicationContext(), "Failed to connect", Toast.LENGTH_SHORT).show();
            e.printStackTrace();

        } catch (FormatException e) {
            // TODO Auto-generated catch block
            Toast.makeText(getApplicationContext(), "Failed Format", Toast.LENGTH_SHORT).show();
            e.printStackTrace();
        }
    }
    else
        Toast.makeText(getApplicationContext(), "Tag unformatable or already formatted to Ndef.", Toast.LENGTH_LONG).show();

}

Does anyone know what the error might be and why the code works for the 1k chips and not the Ultralight C? The tag is brand new and completely blank.

This is the output in logcat:

    04-21 08:49:27.300: W/System.err(9351): java.io.IOException
04-21 08:49:27.300: W/System.err(9351):     at android.nfc.tech.NdefFormatable.format(NdefFormatable.java:132)
04-21 08:49:27.300: W/System.err(9351):     at android.nfc.tech.NdefFormatable.format(NdefFormatable.java:95)
04-21 08:49:27.300: W/System.err(9351):     at com.example.exjobb.nfc.FormatTag.formatTag(FormatTag.java:69)
04-21 08:49:27.300: W/System.err(9351):     at com.example.exjobb.nfc.FormatTag.onNewIntent(FormatTag.java:58
04-21 08:49:27.300: W/System.err(9351):     at android.app.Instrumentation.callActivityOnNewIntent(Instrumentation.java:1178)
04-21 08:49:27.300: W/System.err(9351):     at android.app.ActivityThread.deliverNewIntents(ActivityThread.java:2418)
04-21 08:49:27.300: W/System.err(9351):     at android.app.ActivityThread.performNewIntents(ActivityThread.java:2431)
04-21 08:49:27.300: W/System.err(9351):     at android.app.ActivityThread.handleNewIntent(ActivityThread.java:2440)
04-21 08:49:27.300: W/System.err(9351):     at android.app.ActivityThread.access$1500(ActivityThread.java:159)
04-21 08:49:27.300: W/System.err(9351):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1387)
04-21 08:49:27.300: W/System.err(9351):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-21 08:49:27.300: W/System.err(9351):     at android.os.Looper.loop(Looper.java:176)
04-21 08:49:27.300: W/System.err(9351):     at android.app.ActivityThread.main(ActivityThread.java:5419)
04-21 08:49:27.300: W/System.err(9351):     at java.lang.reflect.Method.invokeNative(Native Method)
04-21 08:49:27.300: W/System.err(9351):     at java.lang.reflect.Method.invoke(Method.java:525)
04-21 08:49:27.305: W/System.err(9351):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
04-21 08:49:27.305: W/System.err(9351):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
04-21 08:49:27.305: W/System.err(9351):     at dalvik.system.NativeStart.main(Native Method)

回答1:

I made the formating work by adding an other filter to the ForegroundDispatch filter. Before i was only filtering for a tag discovery but after adding Tech discovery it seems to be working.

IntentFilter tagDetected = new IntentFilter(NfcAdapter.ACTION_TAG_DISCOVERED);
IntentFilter techDetected = new IntentFilter(NfcAdapter.ACTION_TECH_DISCOVERED);
IntentFilter[] nfcIntentFilter = new IntentFilter[]{tagDetected,techDetected};

nfcAdapter.enableForegroundDispatch(this, nfcPendingIntent, nfcIntentFilter, null);

Don't forget to add the new filter to your onNewIntent Method.

来源：https://stackoverflow.com/questions/29745097/formatting-a-mifare-ultralight-c-to-ndef