我一直在尝试创建一个可以读取两种不同类型的 NFC 标签的应用程序。一个应该是 HCE-IsoDep，在 Nexus 5 上模拟，一个是 Ndef-tag。但是我遇到了一个小问题：
我设法阅读这两种类型的标签，但不是我想要的方式。Ndef 标签完全没有问题。当我尝试读取 HCE 标签时，我遇到了问题。我只能在手机打开时读取标签，我模拟标签被锁定（屏幕打开，但锁定打开）。每当我解锁屏幕时，它就不会再进行交互了，据我所知，它会尝试发送。
如果我尝试在没有 的情况下onNewIntent直接进入 a onTagDiscovered，它在 HCE 设备被锁定和解锁时都可以工作，但是我无法读取 Ndef 标记。在 logcat 中，我收到消息：NfcService LLCP Activation Message当我在解锁时读取 HCE-tag 时。
锁定后，我收到消息：（NativeNfcTag Connect to a tag with a different handle在此之前我收到audio_hw_primary select_devices: out_snd_device(2: speaker) in_snd_device(0: )：）
我的代码如下所示：
主要的：
public class NfcReader extends Activity implements OnMessageReceived {
private static String TAG = NfcReader.class.getSimpleName();
private Button sendButton;
private ProgressBar callProgress;
private NfcAdapter nfcAdapter;
private PendingIntent pIntent;
private IntentFilter[] writeTagFilters;
private String[][] mTechLists;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView dateView = (TextView) findViewById(R.id.dateTextView);
nfcAdapter = NfcAdapter.getDefaultAdapter(this);
pIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
IntentFilter tagDetected = new IntentFilter(NfcAdapter.ACTION_TAG_DISCOVERED);
writeTagFilters = new IntentFilter[] { tagDetected };
mTechLists = new String[][] {new String[] {
Ndef.class.getName(),
IsoDep.class.getName()
}};
}
@Override
protected void onPause() {
super.onPause();
disableForegroundMode();
}
@Override
protected void onResume() {
super.onResume();
enableForegroundMode();
}
public void enableForegroundMode() {
Log.d(TAG, "onResume");
nfcAdapter.enableForegroundDispatch(this, pIntent, writeTagFilters, mTechLists);
}
public void disableForegroundMode() {
Log.d(TAG, "onPause");
nfcAdapter.disableForegroundDispatch(this);
}
@Override
public void onNewIntent(Intent intent) {
Log.d(TAG, "onNewIntent");
if(NfcAdapter.ACTION_TAG_DISCOVERED.equals(intent.getAction())){
Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
Ndef nDef = Ndef.get(tag);
if (nDef != null) {
onNdefDiscovered(tag);
}
else {
onTagDiscovered(tag);
}
}
}
public void onNdefDiscovered(Tag tag) {
Log.d(TAG, "Ndef found");
new ReadTag().execute(tag);
}
public void onTagDiscovered(Tag tag) {
Log.d(TAG, "HCEfound");
IsoDep isoDep = IsoDep.get(tag);
IsoDepTransceiver transceiver = new IsoDepTransceiver(isoDep, this);
transceiver.run();
}
@Override
public void onMessage(final byte[] message) {
runOnUiThread(new Runnable() {
@Override
public void run() {
String readFromHce = new String(message);
TextView result = (TextView) findViewById(R.id.refTextView);
result.setText(readFromHce);
}
});
}
@Override
public void onError(Exception exception) {
onMessage(exception.getMessage().getBytes());
}
}
显现：
<uses-sdk
android:minSdkVersion="19"
android:targetSdkVersion="19" />
<uses-permission
android:name="android.permission.INTERNET" />
<uses-permission
android:name="android.permission.NFC" />
<uses-feature
android:name="android.hardware.nfc"
android:required="true" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:name=".HceReader"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
<action android:name="android.nfc.action.NDEF_DISCOVERED"/>
<action android:name="android.nfc.action.TECH_DISCOVERED"/>
<action android:name="android.nfc.action.TAG_DISCOVERED" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="text/plain" />
</intent-filter>
<meta-data
android:name="android.nfc.action.TECH_DISCOVERED"
android:resource="@xml/filter_nfc"/>
filter_nfc.xml
<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
<tech-list>
<tech>android.nfc.tech.IsoDep</tech>
</tech-list>
<tech-list>
<tech>android.nfc.tech.Ndef</tech>
</tech-list>
</resources>
有谁知道我做错了什么？我已经搜索了很多，但没有找到解决方案。再说一遍。我可以毫无问题地阅读 Ndef 标记。当 HCE 设备上的屏幕被锁定时，我只能读取模拟的 IsoDep 标记。
感谢您的帮助
问候
编辑：下面的代码正在工作
public class NfcReader extends Activity implements OnMessageReceived, ReaderCallback {
private static String TAG = NfcReader.class.getSimpleName();
private NfcAdapter nfcAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView result = (TextView) findViewById(R.id.refTextView);
nfcAdapter = NfcAdapter.getDefaultAdapter(this);
}
@Override
protected void onPause() {
super.onPause();
nfcAdapter.disableReaderMode(this);
}
@Override
protected void onResume() {
super.onResume();
nfcAdapter.enableReaderMode(this, this, NfcAdapter.FLAG_READER_NFC_A, null);
}
public void onTagDiscovered(Tag tag) {
Log.d(TAG, "Tag Found");
Ndef nDef = Ndef.get(tag);
IsoDep isoDep = IsoDep.get(tag);
if (nDef != null) {
new ReadTag().execute(tag);
}
else if (isoDep != null){
IsoDepTransceiver transceiver = new IsoDepTransceiver(isoDep, this);
transceiver.run();
}
}
@Override
public void onMessage(final byte[] message) {
runOnUiThread(new Runnable() {
@Override
public void run() {
String readFromHce = new String(message);
TextView result = (TextView) findViewById(R.id.refTextView);
result.setText(readFromHce);
}
});
}
@Override
public void onError(Exception exception) {
onMessage(exception.getMessage().getBytes());
}
}
非常感谢 NFC 家伙的提示。