我正在创建一个应用程序，我想要读取NFC序列号，存储它（可能是共享偏好），然后使用SN触发操作，如果它是真的。
我已将我的项目上传到GitHub，希望能更好地解释我想要做的事情。 https://github.com/soboapps/PunchCard
我找到了一些读取NFC标签的代码，它运行良好。我已将它集成到我的应用程序中，但我的努力是尝试提取标记的各个部分。
有人可以告诉我如何得到我认为的内容
resolveIntent(Intent intent)
byte[] id = intent.getByteArrayExtra(NfcAdapter.EXTRA_ID);
但我无法弄清楚如何将其转换为String，以便我可以存储它。
这是整个班级。这段代码附带了其他类，但我认为我需要的是在这里。
package com.soboapps.compare;
import android.app.AlertDialog;
import android.app.PendingIntent;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.res.Configuration;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.MifareClassic;
import android.nfc.tech.MifareUltralight;
import android.os.Bundle;
import android.os.Parcelable;
import android.provider.Settings;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.support.v7.app.AppCompatActivity;
import android.support.design.widget.NavigationView;
import android.os.Handler;
import android.widget.LinearLayout;
import android.widget.TextView;
import java.nio.charset.Charset;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import com.soboapps.compare.record.ParsedNdefRecord;
public class MainActivity extends AppCompatActivity implements
NavigationView.OnNavigationItemSelectedListener {
public static final String TAG = "NfcDemo";
//Declaration
private static final String NAV_ITEM_ID = "navItemId" ;
private static final long DRAWER_CLOSE_DELAY_MS = 300 ;
private DrawerLayout mDrawerLayout;
private int mNavItemId;
private ActionBarDrawerToggle mDrawerToggle;
private final CofFragment mCofFragment= new CofFragment();
private final SandFragment mSandFragment = new SandFragment();
private final Handler mDrawerActionHandler = new Handler();
private static final DateFormat TIME_FORMAT = SimpleDateFormat.getDateTimeInstance();
private LinearLayout mTagContent;
private NfcAdapter mAdapter;
private PendingIntent mPendingIntent;
private NdefMessage mNdefPushMessage;
private AlertDialog mDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Initialize Drawer layout -> activity_main
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
//Initialize Toolbar android.support.v7.widget.Toolbar
Toolbar mToolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(mToolbar);
//Load saved navigation state if present
if (null==savedInstanceState){
mNavItemId = R.id.drawer_item_1;
}else{
mNavItemId = savedInstanceState.getInt(NAV_ITEM_ID);
}
// Listen to navigation events
NavigationView navigationView = (NavigationView) findViewById(R.id.navigation);
navigationView.setNavigationItemSelectedListener(this);
//Select the Correct nav menu item
navigationView.getMenu().findItem(mNavItemId).setChecked(true);
// Setup the humberger icon to open and close drawer
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout, mToolbar, R.string.open, R.string.close);
mDrawerLayout.setDrawerListener(mDrawerToggle);
mDrawerToggle.syncState();
// navigate function to swich between items id
// parameter item id
navigate(mNavItemId);
mTagContent = (LinearLayout) findViewById(R.id.list);
resolveIntent(getIntent());
mDialog = new AlertDialog.Builder(this).setNeutralButton("Ok", null).create();
mAdapter = NfcAdapter.getDefaultAdapter(this);
if (mAdapter == null) {
showMessage(R.string.error, R.string.no_nfc);
finish();
return;
}
mPendingIntent = PendingIntent.getActivity(this, 0,
new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
mNdefPushMessage = new NdefMessage(new NdefRecord[] { newTextRecord(
"Message from NFC Reader :-)", Locale.ENGLISH, true) });
}
private void navigate(final int itemId) {
switch (itemId){
case R.id.drawer_item_1:
//start about fragment
getFragmentManager().beginTransaction().replace(R.id.content,mCofFragment).commit();
break;
case R.id.drawer_item_2:
//start project fragment
getFragmentManager().beginTransaction().replace(R.id.content, mSandFragment).commit();
break;
}
}
private void showMessage(int title, int message) {
mDialog.setTitle(title);
mDialog.setMessage(getText(message));
mDialog.show();
}
private NdefRecord newTextRecord(String text, Locale locale, boolean encodeInUtf8) {
byte[] langBytes = locale.getLanguage().getBytes(Charset.forName("US-ASCII"));
Charset utfEncoding = encodeInUtf8 ? Charset.forName("UTF-8") : Charset.forName("UTF-16");
byte[] textBytes = text.getBytes(utfEncoding);
int utfBit = encodeInUtf8 ? 0 : (1 << 7);
char status = (char) (utfBit + langBytes.length);
byte[] data = new byte[1 + langBytes.length + textBytes.length];
data[0] = (byte) status;
System.arraycopy(langBytes, 0, data, 1, langBytes.length);
System.arraycopy(textBytes, 0, data, 1 + langBytes.length, textBytes.length);
return new NdefRecord(NdefRecord.TNF_WELL_KNOWN, NdefRecord.RTD_TEXT, new byte[0], data);
}
@Override
protected void onResume() {
super.onResume();
if (mAdapter != null) {
if (!mAdapter.isEnabled()) {
showWirelessSettingsDialog();
}
mAdapter.enableForegroundDispatch(this, mPendingIntent, null, null);
mAdapter.enableForegroundNdefPush(this, mNdefPushMessage);
}
}
@Override
protected void onPause() {
super.onPause();
if (mAdapter != null) {
mAdapter.disableForegroundDispatch(this);
mAdapter.disableForegroundNdefPush(this);
}
}
private void showWirelessSettingsDialog() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(R.string.nfc_disabled);
builder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialogInterface, int i) {
Intent intent = new Intent(Settings.ACTION_WIRELESS_SETTINGS);
startActivity(intent);
}
});
builder.setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialogInterface, int i) {
finish();
}
});
builder.create().show();
return;
}
private void resolveIntent(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;
if (rawMsgs != null) {
msgs = new NdefMessage[rawMsgs.length];
for (int i = 0; i < rawMsgs.length; i++) {
msgs[i] = (NdefMessage) rawMsgs[i];
}
} else {
// Unknown tag type
byte[] empty = new byte[0];
byte[] id = intent.getByteArrayExtra(NfcAdapter.EXTRA_ID);
Parcelable tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
byte[] payload = dumpTagData(tag).getBytes();
NdefRecord record = new NdefRecord(NdefRecord.TNF_UNKNOWN, empty, id, payload);
NdefMessage msg = new NdefMessage(new NdefRecord[] { record });
msgs = new NdefMessage[] { msg } ;
}
// Setup the views
buildTagViews(msgs);
}
//To display the UID
}
private String dumpTagData(Parcelable p) {
StringBuilder sb = new StringBuilder();
Tag tag = (Tag) p;
byte[] id = tag.getId();
sb.append("Tag ID (hex): ").append(getHex(id)).append("\n");
sb.append("Tag ID (dec): ").append(getDec(id)).append("\n");
sb.append("ID (reversed): ").append(getReversed(id)).append("\n");
String prefix = "android.nfc.tech.";
sb.append("Technologies: ");
for (String tech : tag.getTechList()) {
sb.append(tech.substring(prefix.length()));
sb.append(", ");
}
sb.delete(sb.length() - 2, sb.length());
for (String tech : tag.getTechList()) {
if (tech.equals(MifareClassic.class.getName())) {
sb.append('\n');
MifareClassic mifareTag = MifareClassic.get(tag);
String type = "Unknown";
switch (mifareTag.getType()) {
case MifareClassic.TYPE_CLASSIC:
type = "Classic";
break;
case MifareClassic.TYPE_PLUS:
type = "Plus";
break;
case MifareClassic.TYPE_PRO:
type = "Pro";
break;
}
sb.append("Mifare Classic type: ");
sb.append(type);
sb.append('\n');
sb.append("Mifare size: ");
sb.append(mifareTag.getSize() + " bytes");
sb.append('\n');
sb.append("Mifare sectors: ");
sb.append(mifareTag.getSectorCount());
sb.append('\n');
sb.append("Mifare blocks: ");
sb.append(mifareTag.getBlockCount());
}
if (tech.equals(MifareUltralight.class.getName())) {
sb.append('\n');
MifareUltralight mifareUlTag = MifareUltralight.get(tag);
String type = "Unknown";
switch (mifareUlTag.getType()) {
case MifareUltralight.TYPE_ULTRALIGHT:
type = "Ultralight";
break;
case MifareUltralight.TYPE_ULTRALIGHT_C:
type = "Ultralight C";
break;
}
sb.append("Mifare Ultralight type: ");
sb.append(type);
}
}
return sb.toString();
}
private String getHex(byte[] bytes) {
StringBuilder sb = new StringBuilder();
for (int i = bytes.length - 1; i >= 0; --i) {
int b = bytes[i] & 0xff;
if (b < 0x10)
sb.append('0');
sb.append(Integer.toHexString(b));
if (i > 0) {
sb.append(" ");
}
}
return sb.toString();
}
private long getDec(byte[] bytes) {
long result = 0;
long factor = 1;
for (int i = 0; i < bytes.length; ++i) {
long value = bytes[i] & 0xffl;
result += value * factor;
factor *= 256l;
}
return result;
}
private long getReversed(byte[] bytes) {
long result = 0;
long factor = 1;
for (int i = bytes.length - 1; i >= 0; --i) {
long value = bytes[i] & 0xffl;
result += value * factor;
factor *= 256l;
}
return result;
}
void buildTagViews(NdefMessage[] msgs) {
if (msgs == null || msgs.length == 0) {
return;
}
LayoutInflater inflater = LayoutInflater.from(this);
LinearLayout content = mTagContent;
// Parse the first message in the list
// Build views for all of the sub records
Date now = new Date();
List<ParsedNdefRecord> records = NdefMessageParser.parse(msgs[0]);
final int size = records.size();
for (int i = 0; i < size; i++) {
TextView timeView = new TextView(this);
timeView.setText(TIME_FORMAT.format(now));
content.addView(timeView, 0);
ParsedNdefRecord record = records.get(i);
content.addView(record.getView(this, inflater, content, i), 1 + i);
content.addView(inflater.inflate(R.layout.tag_divider, content, false), 2 + i);
}
}
@Override
public void onConfigurationChanged(final Configuration newConfig){
super.onConfigurationChanged(newConfig);
mDrawerToggle.onConfigurationChanged(newConfig);
}
@Override
public void onBackPressed(){
if(mDrawerLayout.isDrawerOpen(GravityCompat.START)){
mDrawerLayout.closeDrawer(GravityCompat.START);
}else{
super.onBackPressed();
}
}
@Override
public void onSaveInstanceState(final Bundle outState){
super.onSaveInstanceState(outState);
outState.putInt(NAV_ITEM_ID, mNavItemId);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
final int id = item.getItemId();
if(id== android.support.v7.appcompat.R.id.home){
return mDrawerToggle.onOptionsItemSelected(item);
}
return super.onOptionsItemSelected(item);
}
/**
* -Handles clicks on the navigation menu
* @param menuItem
* @return
*/
@Override
public boolean onNavigationItemSelected(final MenuItem menuItem) {
//Update highlighted item in the navigation menu
menuItem.setChecked(true);
mNavItemId = menuItem.getItemId();
// Time gap after closing the navigation to see animation
mDrawerLayout.closeDrawer(GravityCompat.START);
mDrawerActionHandler.postDelayed(new Runnable() {
@Override
public void run() {
navigate(menuItem.getItemId());
}
}, DRAWER_CLOSE_DELAY_MS);
return true;
}
@Override
public void onNewIntent(Intent intent) {
setIntent(intent);
resolveIntent(intent);
}
}
编辑：
我添加了我认为的建议。 IO现在在“上下文”中收到错误，但实际上我只是想知道这是否是建议的内容？
private String getHex(byte[] bytes) {
StringBuilder sb = new StringBuilder();
for (int i = bytes.length - 1; i >= 0; --i) {
int b = bytes[i] & 0xff;
if (b < 0x10)
sb.append('0');
sb.append(Integer.toHexString(b));
if (i > 0) {
sb.append(" ");
}
}
return sb.toString();
final SharedPreferences prefs = context.getSharedPreferences("CHECK_POINT_NAME",Context.MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
editor.putString("CHECK_POINT", String.valueOf(sb));
editor.apply();
}
答案 0 :(得分：1)
如果您想将byte[]转换为String，请填写
String s = new String(id);
修改 来自here
String ByteArrayToHexString(byte [] inarray)
{
int i, j, in;
String [] hex = {"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"};
String out= "";
for(j = 0 ; j < inarray.length ; ++j)
{
in = (int) inarray[j] & 0xff;
i = (in >> 4) & 0x0f;
out += hex[i];
i = in & 0x0f;
out += hex[i];
}
return out;
}
答案 1 :(得分：1)
在代码中实际上有一个方法可以将字节数组转换为十六进制字符串。它叫做getHex（）。您可以将NFC ID字节数组传递给它，以获取可以存储的十六进制字符串，并与其他ID进行比较，以查看它是否与另一个序列号匹配。
答案 2 :(得分：0)
我为我的项目找到了更好的答案。我添加了nfcTagSerialNum作为公共静态字符串，然后我将以下内容添加到我的resolveIntent（Internet intent）
Tag tagFromIntent = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
byte[] extraID = tagFromIntent.getId();
StringBuilder sb = new StringBuilder();
for (byte b : extraID) {
sb.append(String.format("%02X", b));
};
nfcTagSerialNum = sb.toString();
Log.e("nfc ID", nfcTagSerialNum);
然后我可以在任何我想要的地方使用字符串“nfcTagSerialNum”。