Android 读取NFC卡卡号

1.权限

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2.注册(静态)

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3.Activity

• 初始化

        //初始化NfcAdapter
        mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
                // 初始化PendingIntent，当有NFC设备连接上的时候，就交给当前Activity处理
        pi = PendingIntent.getActivity(this, 0, new Intent(this, getClass())
                .addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);

• 启动

    @Override
    protected void onResume() {
        super.onResume();
        mNfcAdapter.enableForegroundDispatch(this, pi, null, null); //启动
    }

• 获取数据

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        // 当前app正在前端界面运行，这个时候有intent发送过来，那么系统就会调用onNewIntent回调方法，将intent传送过来
        // 我们只需要在这里检验这个intent是否是NFC相关的intent，如果是，就调用处理方法
        if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(intent.getAction())) {
            processIntent(intent);
        }
    }

• 解析

    /**
     * Parses the NDEF Message from the intent and prints to the TextView
     */
    private void processIntent(Intent intent) {
        //取出封装在intent中的TAG
        Tag tagFromIntent = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
        String CardId =ByteArrayToHexString(tagFromIntent.getId());
    }
private 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;
    }

4.完整参考

package cn.com.jslh.zjcdprogrect.saoka;

import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import cn.com.jslh.zjcdprogrect.R;

public class WorkActivity extends AppCompatActivity {

    private NfcAdapter mNfcAdapter;
    private PendingIntent pi;
    private IntentFilter tagDetected;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_work);

        //初始化NfcAdapter
        mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
        //初始化PendingIntent
        // 初始化PendingIntent，当有NFC设备连接上的时候，就交给当前Activity处理
        pi = PendingIntent.getActivity(this, 0, new Intent(this, getClass())
                .addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
        // 新建IntentFilter，使用的是第二种的过滤机制
//        tagDetected = new IntentFilter(NfcAdapter.ACTION_TECH_DISCOVERED);
//        tagDetected.addCategory(Intent.CATEGORY_DEFAULT);
    }

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        // 当前app正在前端界面运行，这个时候有intent发送过来，那么系统就会调用onNewIntent回调方法，将intent传送过来
        // 我们只需要在这里检验这个intent是否是NFC相关的intent，如果是，就调用处理方法
        if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(intent.getAction())) {
            processIntent(intent);
        }
    }

    @Override
    protected void onResume() {
        super.onResume();
        mNfcAdapter.enableForegroundDispatch(this, pi, null, null);
    }

    /**
     * Parses the NDEF Message from the intent and prints to the TextView
     */
    private void processIntent(Intent intent) {
        //取出封装在intent中的TAG
        Tag tagFromIntent = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
        String CardId =ByteArrayToHexString(tagFromIntent.getId());
    }

    public static void startActivity(Context context){
        Intent intent = new Intent();
        intent.setClass(context,WorkActivity.class);
        context.startActivity(intent);
    }

    private 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;
    }
}