Android NFC java.io.IOException:Transceive失败

Question

我正在开发一个可以在NFC标签上读写的Android应用程序.我在读取已经写过的标签时没有问题,但是当我使用空白标签时,我很难在HEX代码中读取标签的UID.

我正在使用mifare经典标签,我使用readblock方法直接在十六进制中读取UID.奇怪的是,它在调试器模式下完美运行,我获得了UID.但是当我在没有debbuger的情况下尝试时,我得到以下异常:

   java.io.IOException: Transceive failed

这是我读取标记的方法:

    static String getUID(Intent intent) {

    Tag tagFromIntent = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
    MifareClassic mc = MifareClassic.get(tagFromIntent);

    try {
        mc.connect();
        Log.i("connect", "ok");
    } catch (IOException e) {
        // TODO Auto-generated catch block
        Log.i("connect", "nok");
        e.printStackTrace();
    }
    try {
        boolean secA = mc.authenticateSectorWithKeyA(0, mc.KEY_DEFAULT);
        Log.i("secA", "ok");
    } catch (IOException e) {
        Log.i("secA", "nok");
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    try {
        boolean secB = mc.authenticateSectorWithKeyB(0, mc.KEY_DEFAULT);
        Log.i("secB", "ok");
    } catch (IOException e) {
        Log.i("secB", "nok");
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    byte[] uidBytes = null;

    try {

        uidBytes = mc.readBlock(0);
        Log.i("bytes", "ok");

    } catch (IOException e) {
        Log.i("bytes", "nok");
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    try {

        mc.close();
        Log.i("close", "ok");
    } catch (IOException e) {
        Log.i("close", "nok");
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    if (uidBytes != null) {
    String uid = HexToString(uidBytes);

    return uid;
    }
    else { return "Repasser le tag";}
}

我不知道如何解决这个问题,因为它在调试模式下工作.

Answer 1

可能存在身份验证问题。您可以通过这种方式验证这一点......

if (mfc.authenticateSectorWithKeyA(sectorNumber,
                MifareClassic.KEY_MIFARE_APPLICATION_DIRECTORY)) {
            Log.d("TAG", "Authorized sector with MAD key");

        } else if (mfc.authenticateSectorWithKeyA(
                sectorNumber, MifareClassic.KEY_DEFAULT)) {
            Log.d("TAG",
                    "Authorization granted to sector  with DEFAULT key");

        } else if (mfc
                .authenticateSectorWithKeyA(sectorNumber,
                        MifareClassic.KEY_NFC_FORUM)) {
            Log.d("TAG",
                    "Authorization granted to sector with NFC_FORUM key");

        } else {
            Log.d("TAG", "Authorization denied ");

            return false;
        }

这里的 SectorNumber 是：您要验证的扇区。例如：0,1,2....15 for mifare Classic 1K 当身份验证完成后，您可以读取或写入。