android nfc MifareUltralight读写

MifareUltralight :是techlist中的一种类型，共16页，每页4个字节，也就是一页只能存2个汉字或者4个字母,0到3页 也就是前四页用来存卡片信息的，所以往MifareUltralight写数据，只能从第四页开始写，总共可以写入除了自带的卡片信息，可以写入4到15页数据，也就是56个字节，折算出来就是最多可写28个汉字或者56个字符。

找MifareUltralight 卡片靠近手机摄像头附近 即可测试 demo地址

http://download.csdn.net/detail/u012303938/9282985

源码：

package com.example.writefnc;

import java.io.IOException;
import java.nio.charset.Charset;
import java.util.Arrays;

import android.support.v7.app.ActionBarActivity;
import android.app.PendingIntent;
import android.content.Intent;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.MifareUltralight;
import android.nfc.tech.Ndef;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.CheckBox;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends ActionBarActivity {

private NfcAdapter nfcAdapter;
private PendingIntent intent;
CheckBox checkBox1;
TextView textView1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
checkBox1=(CheckBox) findViewById(R.id.checkBox1);
textView1=(TextView) findViewById(R.id.textView1);
nfcAdapter=NfcAdapter.getDefaultAdapter(this);
intent=PendingIntent.getActivity(this, 0, new Intent(this,getClass()), 0);
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
nfcAdapter.enableForegroundDispatch(this, intent, null, null);
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
nfcAdapter.disableForegroundDispatch(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

@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.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
protected void onNewIntent(Intent intent) {
// TODO Auto-generated method stub
super.onNewIntent(intent);
Tag tag=intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
Toast.makeText(this, "获取tag", Toast.LENGTH_SHORT).show();
if(checkBox1.isChecked()){
Toast.makeText(this, "选择读取", Toast.LENGTH_SHORT).show();
textView1.setText(readTag(tag));
}else{
Toast.makeText(this, "选择写入", Toast.LENGTH_SHORT).show();
writeTag(tag);
}

}
public void writeTag(Tag tag){
String[] techlist=tag.getTechList();
if(Arrays.toString(techlist).contains("MifareUltralight")){
MifareUltralight mifareUltralight=MifareUltralight.get(tag);
try {
mifareUltralight.connect();
Toast.makeText(this, "开始写", Toast.LENGTH_SHORT).show();
mifareUltralight.writePage(4, "你好".getBytes(Charset.forName("GB2312")));
mifareUltralight.writePage(5, "中国".getBytes(Charset.forName("GB2312")));
mifareUltralight.writePage(6, "人们".getBytes(Charset.forName("GB2312")));
mifareUltralight.writePage(7, "百姓".getBytes(Charset.forName("GB2312")));			mifareUltralight.writePage(7, "百姓".getBytes(Charset.forName("GB2312")));

Toast.makeText(this, "写入完成", Toast.LENGTH_SHORT).show();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
mifareUltralight.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}else{
Toast.makeText(this, "不是MifareUltralightle类型", Toast.LENGTH_SHORT).show();
}

}
public String readTag(Tag tag){
String[] techlist=tag.getTechList();
if(Arrays.toString(techlist).contains("MifareUltralight")){
MifareUltralight mifareUltralight=MifareUltralight.get(tag);
Toast.makeText(this, "开始读", Toast.LENGTH_SHORT).show();
try {
mifareUltralight.connect();

byte[] data=mifareUltralight.readPages(4);
return new String(data,Charset.forName("GB2312"));

} catch (Exception e) {
// TODO: handle exception
}finally{
try {
mifareUltralight.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}else{
Toast.makeText(this, "不是MifareUltralightle类型", Toast.LENGTH_SHORT).show();
}
return null;
}

}