Android實現讀取NFC卡卡號示例

Android實現讀取NFC卡卡號示例，具體如下：

1.權限

  <uses-permission android:name="android.permission.NFC" />
    <uses-feature
    android:name="android.hardware.nfc"
    android:required="true" />

2.注冊(靜態)

      <intent-filter>
        <action android:name="android.nfc.action.TAG_DISCOVERED" />
        <data android:mimeType="text/plain" />
      </intent-filter>

3.Activity

初始化

    //初始化NfcAdapter
    mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
        // 初始化PendingIntent，當有NFC設備連接上的時候，就交給當前Activity處理
    pi = PendingIntent.getActivity(this, 0, new Intent(this, getClass())
        .addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);

啟動

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

獲取數據

  @Override
  protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    // 當前app正在前端界面運行，這個時候有intent發送過來，那麼系統就會調用onNewIntent回調方法，將intent傳送過來
    // 我們只需要在這裡檢驗這個intent是否是NFC相關的intent，如果是，就調用處理方法
    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) {
    //取出封裝在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.完整參考

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="cn.com.jslh.zjcdprogrect">

  <uses-permission android:name="android.permission.NFC" />
  <uses-permission android:name="android.permission.INTERNET" />

  <uses-feature
    android:name="android.hardware.nfc"
    android:required="true" />

  <application
    android:name=".common.MyApplication"
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".LoginActivity">
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />

        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
    <activity android:name=".saoka.WorkActivity">
      <intent-filter>
        <action android:name="android.nfc.action.TAG_DISCOVERED" />
        <data android:mimeType="text/plain" />
      </intent-filter>
      <!--<meta-data android:name="android.nfc.action.TECH_DISCOVERED" android:resource="@xml/nfc_tech_filter" />-->
    </activity>
  </application>

</manifest>

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，當有NFC設備連接上的時候，就交給當前Activity處理
    pi = PendingIntent.getActivity(this, 0, new Intent(this, getClass())
        .addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
    // 新建IntentFilter，使用的是第二種的過濾機制
//    tagDetected = new IntentFilter(NfcAdapter.ACTION_TECH_DISCOVERED);
//    tagDetected.addCategory(Intent.CATEGORY_DEFAULT);
  }

  @Override
  protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    // 當前app正在前端界面運行，這個時候有intent發送過來，那麼系統就會調用onNewIntent回調方法，將intent傳送過來
    // 我們只需要在這裡檢驗這個intent是否是NFC相關的intent，如果是，就調用處理方法
    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) {
    //取出封裝在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;
  }
}

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