如何读取数据？
Tag tagFromIntent = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
NfcA nfcA = NfcA.get(tag);
nfcA.connect();
byte[] SELECT = {(byte) 0x30, (byte) 0x05};//我读取的NFC卡片使用的是NTAG216的芯片，这里的指令参数是根据其datasheet的说明写的。
byte[] result = nfcA.transceive(SELECT);//这里会返回16个字节的数据，根据芯片不同会有差异
该芯片的快速读写命令是0x3A，可以指定读取页数范围，在使用快速读写命令时，发现读取范围超过70字节android就会报错，所以使用了每次最多读取64字节的方式。
package com.yorkg.android.nfc; import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Arrays; import android.app.Activity;
import android.app.AlertDialog;
import android.app.PendingIntent;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.MifareClassic;
import android.nfc.tech.NfcA;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast; import com.yorkg.android.nfc.dataobject.mifare.MifareBlock;
import com.yorkg.android.nfc.dataobject.mifare.MifareClassCard;
import com.yorkg.android.nfc.dataobject.mifare.MifareSector;
import com.yorkg.android.nfc.util.Converter; public class MyFirstNFCDemoActivity extends Activity {
/** Called when the activity is first created. */ private Button clearBtn = null; private EditText sealCompanyName = null;
private EditText sealName = null;
private EditText sealNumber = null;
private EditText sealTaxId = null;
private EditText sealCode = null;
private EditText sealMaterial = null;
private EditText sealSize = null; private EditText companyMadedName = null;
private EditText companyMadedTime = null; private EditText companyCheckedName = null; private NfcAdapter mAdapter;
private PendingIntent mPendingIntent;
private IntentFilter[] mFilters;
private String[][] mTechLists; private static final int AUTH = 1;
private static final int EMPTY_BLOCK_0 = 2;
private static final int EMPTY_BLOCK_1 = 3;
private static final int NETWORK = 4;
private static final int NFC_OFF = 5;
private static final int NFC_TYPE_ERROR = 6;
private static final String TAG = "NfcDemo"; private static boolean READ_LOCK = false; private void initView(){
sealCompanyName = (EditText) this.findViewById(R.id.edittext_seal_company_name);
sealName = (EditText) this.findViewById(R.id.edittext_seal_name);
sealNumber = (EditText) this.findViewById(R.id.edittext_seal_number);
sealTaxId = (EditText) this.findViewById(R.id.edittext_tax_id);
sealCode = (EditText) this.findViewById(R.id.edittext_code);
sealMaterial = (EditText) this.findViewById(R.id.edittext_seal_material);
sealSize = (EditText) this.findViewById(R.id.edittext_seal_size); companyMadedName = (EditText) this.findViewById(R.id.edittext_company_maded_name);
companyMadedTime = (EditText) this.findViewById(R.id.edittext_company_maded_time); companyCheckedName = (EditText) this.findViewById(R.id.edittext_company_checked_name); clearBtn = (Button) this.findViewById(R.id.clear_btn);
clearBtn.setOnClickListener(new OnClickListener() { @Override
public void onClick(View v) {
// TODO Auto-generated method stub
cleanData();
}
});
} //清除数据信息
private void cleanData(){
sealCompanyName.setText("");
sealName.setText("");
sealNumber.setText("");
sealTaxId.setText("");
sealCode.setText("");
sealMaterial.setText("");
sealSize.setText("");
companyMadedName.setText("");
companyMadedTime.setText("");
companyCheckedName.setText("");
} @Override
public void onCreate(Bundle savedState) {
super.onCreate(savedState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main); initView(); mAdapter = NfcAdapter.getDefaultAdapter(this);
mPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this,getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0); // Setup an intent filter for all MIME based dispatches
IntentFilter ndef = new IntentFilter(NfcAdapter.ACTION_TECH_DISCOVERED);
// try {
// ndef.addDataType("*/*");
// } catch (MalformedMimeTypeException e) {
// throw new RuntimeException("fail", e);
// }
mFilters = new IntentFilter[] { ndef, };
mTechLists = new String[][] { new String[] { MifareClassic.class
.getName() } , new String[] {NfcA.class.getName()}}; //得到是否检测到ACTION_TECH_DISCOVERED触发
if (NfcAdapter.ACTION_TECH_DISCOVERED.equals(getIntent().getAction())) {
//处理该intent
resolveIntentNfcA(getIntent());
}
} @Override
public void onResume() {
super.onResume(); if (mAdapter!=null && (!mAdapter.isEnabled())) {
showAlert(NFC_OFF, getString(R.string.error5));
} if (mAdapter!=null) {
mAdapter.enableForegroundDispatch(this, mPendingIntent, mFilters,
mTechLists);
} } @Override
public void onNewIntent(Intent intent) {
resolveIntentNfcA(intent);
} @Override
public void onPause() {
super.onPause();
if (mAdapter!=null){
mAdapter.disableForegroundDispatch(this);
}
}
void resolveIntentNfcA(Intent intent){
if (READ_LOCK==false){
READ_LOCK = true;
Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG); if (NfcAdapter.ACTION_TECH_DISCOVERED.equals(intent.getAction()))
{
Tag tagFromIntent = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
MyLog.i(TAG, Arrays.toString(tagFromIntent.getTechList())); try
{
NfcA nfcA = NfcA.get(tag);
nfcA.connect();
byte[] SELECT = {
(byte) 0x30,
(byte) 0x05,
}; byte[] result = nfcA.transceive(SELECT);
int data_len = ((result[0]&0x0f)<<8)+((result[1]&0xff));
MyLog.i(TAG, "是否已写入数据"+result[0]+"，写入数据长度："+data_len);
byte[] buf_res = new byte[data_len/2+4];
if (result[0]!=0 && data_len!=0){
int count = data_len/2/64;
int i = 0;
for (i=0; i<count; i++){
// //读取数据
byte[] DATA_READ = {
(byte) 0x3A,
(byte) (0x06+i*(64/4)),
(byte) (0x06+(i+1)*(64/4))
// (byte) (5+data_len/8)
};
byte[] data_res = nfcA.transceive(DATA_READ);
System.arraycopy(data_res, 0, buf_res, i*64, 64);
MyLog.i(TAG, "读卡成功");
}
if (((data_len/2)%(64))!=0){
byte[]DATA_READ = {
(byte) 0x3A,
(byte) (0x06+i*(64/4)),
(byte) (((0x06+i*(64/4))+(data_len/2/4)%(64/4))-1)
// (byte) (5+data_len/8)
};
byte[] data_res = nfcA.transceive(DATA_READ);
System.arraycopy(data_res, 0, buf_res, i*64, (data_len/2)%64);
MyLog.i(TAG, "读卡成功2");
}
String res = gb2312ToString(buf_res);
MyLog.i(TAG, "stringBytes:"+res);
showNFCInfo(res);
} }catch(IOException e){
e.printStackTrace();
cleanData();
MyLog.e(TAG, "读卡失败");
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
showAlert(NFC_TYPE_ERROR, getString(R.string.error6));
}finally{ } }
READ_LOCK = false;
}
} //将数据转换为GB2312
private String gb2312ToString(byte[] data) {
String str = null;
try {
str = new String(data, "gb2312");//"utf-8"
} catch (UnsupportedEncodingException e) {
}
return str;
} //将字符串解析显示到页面
private void showNFCInfo(String str){
String[] contents_temp = str.split("\\|");
String[] contents = new String[contents_temp.length]; int i; for (i = 0; i < contents_temp.length; i++) {
contents[i]=contents_temp[i];
}
//目前有10项，所以这里只初始化到第10项
for (int j=i; j<10; j++){
contents[j]="";
} if (contents[0]!=null){
sealCompanyName.setText(contents[0]);
}
if (contents[1]!=null){
sealName.setText(contents[1]);
}
if (contents[2]!=null){
sealNumber.setText(contents[2]);
} if (contents[3]!=null){
sealTaxId.setText(contents[3]);
} if (contents[4]!=null){
sealCode.setText(contents[4]);
} if (contents[5]!=null){
sealMaterial.setText(contents[5]);
}
if (contents[6]!=null){
sealSize.setText(contents[6]);
} if (contents[7]!=null){
companyMadedName.setText(contents[7]);
}
if (contents[8]!=null){
companyMadedTime.setText(contents[8]);
} if (contents[9]!=null){
companyCheckedName.setText(contents[9]);
} } private void showAlert(int alertCase,String str) {
// prepare the alert box
AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
switch (alertCase) { case AUTH:// Card Authentication Error
alertbox.setMessage(getString(R.string.error1));
break;
case EMPTY_BLOCK_0: // Block 0 Empty
alertbox.setMessage(getString(R.string.error2));
break;
case EMPTY_BLOCK_1:// Block 1 Empty
alertbox.setMessage(getString(R.string.error3));
break;
case NETWORK: // Communication Error
alertbox.setMessage(getString(R.string.error4));
break;
case NFC_OFF:
alertbox.setMessage(getString(R.string.error5));
break;
case NFC_TYPE_ERROR:
alertbox.setMessage(getString(R.string.error6));
}
// set a positive/yes button and create a listener
alertbox.setPositiveButton("OK", new DialogInterface.OnClickListener() { // Save the data from the UI to the database - already done
public void onClick(DialogInterface arg0, int arg1) {
clearFields();
}
});
// display box
alertbox.show(); } private void clearFields() { }
}