先说说NFC开发总结，看了几天NFC开发资料，搜集了不少关于这方面的资料、demo、以及他人的总结，android NFC开发
。以下有部分是摘录总结的。因为要是现在总结也是那些，最后附送代码。关于demo我也有，有需要在评论去发邮箱给我。
一、NFC的配置总结
第一：屏幕没有锁住 。 第二：NFC功能已经在设置中打开
当系统检测到一个NFC标签的时候，他会自动去寻找最合适的activity去处理这个intent.
NFC发出的这个Intent将会有三种action:
ACTION_NDEF_DISCOVERED:当系统检测到tag中含有NDEF格式的数据时，且系统中有activity声明可以接受包含NDEF数据的Intent的时候，系统会优先发出这个action的intent。
ACTION_TECH_DISCOVERED：当没有任何一个activity声明自己可以响应ACTION_NDEF_DISCOVERED时，系统会尝试发出TECH的intent.即便你的tag中所包含的数据是NDEF的，但是如果这个数据的MIMEtype或URI不能和任何一个activity所声明的想吻合，系统也一样会尝试发出tech格式的intent，而不是NDEF.
ACTION_TAG_DISCOVERED:当系统发现前两个intent在系统中无人会接受的时候，就只好发这个默认的TAG类型的
二、NFC相关androidManifest文件设置
首先是权限：
然后是sdk级别限制：我个人建议API11开始比较合适：
如果是API8，在代码中，nfc功能设置的代码会出错，要抛出
例如：
NfcAdapter mAdapter = NfcAdapter.getDefaultAdapter(this);
mAdapter.isEnabled()
接着是特殊功能限制：
这个生命可以让你的应用在googleplay上被声明使用者必须拥有nfc功能。
三、NFC标签过滤，也在androidManifest文件设置
在activity的intent过滤xml声明中，你可以同时声明过滤这三种action.但是由之前所说，你应该知道系统在发送intent的时候是有优先级的，所以你最好清楚自己最想处理哪个。
1：过滤ACTION_TAG_DISCOVERED:
<intent-filter><category android:name="android.intent.category.DEFAULT"></category></intent-filter>这个最简单，也是最后一个被尝试接受intent的选项。
2：过滤ACTION_NDEF_DISCOVERED:
<intent-filter><category android:name="android.intent.category.DEFAULT"><data android:mimetype="text/plain"></data></category></intent-filter>其中最重要的应该算是data的mimeType类型了，这个定义的越准确，intent指向你这个activity的成功率就越高，否则系统可能不会发出你想要的NDEF intent了。下面在讲如何使用NDEF写入NFC标签的时候会多举几个类型的例子。
3:过滤ACTION_TECH_DISCOVERED:
你首先需要在你的
一个nfc_tech_filter.xml中可以定义多个
<span><resources xmlns:xliff="urn:oasis:names:tc:xliff:documen</span>t:1.2"><tech-list><tech>android.nfc.tech.IsoDep</tech><tech>android.nfc.tech.NfcA</tech><tech>android.nfc.tech.NfcB</tech><tech>android.nfc.tech.NfcF</tech></tech-list><tech-list><tech>android.nfc.tech.NfcV</tech><tech>android.nfc.tech.Ndef</tech><tech>android.nfc.tech.NdefFormatable</tech><tech>android.nfc.tech.MifareClassic</tech><tech>android.nfc.tech.MifareUltralight</tech></tech-list></resources></span>
在androidManifest文件中声明xml过滤的举例如下：
<intent-filter></intent-filter><meta-data android:name="android.nfc.action.TECH_DISCOVERED" android:resource="@xml/nfc_tech_filter"></meta-data>
四、看具体代码：
1、主要代码实现如下：
package org.reno.Beam;import java.io.ByteArrayOutputStream;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 org.nfc.read.ParsedNdefRecord;import android.app.Activity;import android.app.AlertDialog;import android.app.PendingIntent;import android.content.DialogInterface;import android.content.Intent;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.widget.TextView;public class MainActivity extends Activity { private static final DateFormat TIME_FORMAT = SimpleDateFormat .getDateTimeInstance(); private NfcAdapter mAdapter; private PendingIntent mPendingIntent; private NdefMessage mNdefPushMessage; private TextView promt; private AlertDialog mDialog; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); promt = (TextView) findViewById(R.id.promt); resolveIntent(getIntent()); mDialog = new AlertDialog.Builder(this).setNeutralButton("Ok", null) .create(); // 获取默认的NFC控制器 mAdapter = NfcAdapter.getDefaultAdapter(this); //拦截系统级的NFC扫描，例如扫描蓝牙 mPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0); mNdefPushMessage = new NdefMessage(new NdefRecord[] { newTextRecord("", Locale.ENGLISH, true) }); } @Override protected void onResume() { super.onResume(); if (mAdapter == null) { if (!mAdapter.isEnabled()) { showWirelessSettingsDialog(); } showMessage(R.string.error, R.string.no_nfc); promt.setText("设备不支持NFC！"); return; } if (!mAdapter.isEnabled()) { promt.setText("请在系统设置中先启用NFC功能！"); return; } if (mAdapter != null) { //隐式启动 mAdapter.enableForegroundDispatch(this, mPendingIntent, null, null); mAdapter.enableForegroundNdefPush(this, mNdefPushMessage); } } @Override protected void onPause() { super.onPause(); if (mAdapter != null) { //隐式启动 mAdapter.disableForegroundDispatch(this); mAdapter.disableForegroundNdefPush(this); } } //16进制字符串转换为String private String hexString = "0123456789ABCDEF"; public String decode(String bytes) { if (bytes.length() != 30) { return null; } ByteArrayOutputStream baos = new ByteArrayOutputStream( bytes.length() / 2); // 将每2位16进制整数组装成一个字节 for (int i = 0; i < bytes.length(); i += 2) baos.write((hexString.indexOf(bytes.charAt(i)) << 4 | hexString .indexOf(bytes.charAt(i + 1)))); return new String(baos.toByteArray()); } // 字符序列转换为16进制字符串 private static String bytesToHexString(byte[] src, boolean isPrefix) { StringBuilder stringBuilder = new StringBuilder(); if (isPrefix == true) { stringBuilder.append("0x"); } if (src == null || src.length <= 0) { return null; } char[] buffer = new char[2]; for (int i = 0; i < src.length; i++) { buffer[0] = Character.toUpperCase(Character.forDigit( (src[i] >>> 4) & 0x0F, 16)); buffer[1] = Character.toUpperCase(Character.forDigit(src[i] & 0x0F, 16)); System.out.println(buffer); stringBuilder.append(buffer); } return stringBuilder.toString(); } 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); } 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; } //初步判断是什么类型NFC卡 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); } } //一般公家卡，扫描的信息 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; } //显示NFC扫描的数据 private void buildTagViews(NdefMessage[] msgs) { if (msgs == null || msgs.length == 0) { return; } // 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)); ParsedNdefRecord record = records.get(i); promt.append(record.getViewText()); } } //获取系统隐式启动的 @Override public void onNewIntent(Intent intent) { setIntent(intent); resolveIntent(intent); }}</parsedndefrecord>2、androidManifest配置
<manifest android:versioncode="1" android:versionname="1.0" package="org.reno.Beam" xmlns:android="http://schemas.android.com/apk/res/android"><uses-sdk android:minsdkversion="11" android:targetsdkversion="16"><uses-permission android:name="android.permission.NFC"><uses-feature android:name="android.hardware.nfc"><intent-filter><category android:name="android.intent.category.LAUNCHER"></category></intent-filter><intent-filter><category android:name="android.intent.category.DEFAULT"></category></intent-filter></uses-feature></uses-permission></uses-sdk></manifest>