android rfid 的开发

今天药忘吃喽~ 2022-04-11 04:18 187阅读 0赞

昨天同事找我帮忙看看 rfid 开发的时候，一扫描就直接弹出activity的问题。

网上也有蛮多例子，但是能直接拿来参考写实际项目的没几个，系统提供的demo呢，一扫描标签就弹出activity，也是开发中不想要的。于是进入苦逼模式，进过分析和翻资料、百度、终于解决了。下面是代码：

先看项目图片， 我是直接用demo修改的：  
  
![2cac6c69-e2e1-31a3-a836-229aecb7914f.png][]

1、清单文件：

需求添加权限啦什么，自己看啊，

<?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.nl.nfcdemo"
        android:versionCode="1"
        android:versionName="1.0" >
    
        <uses-sdk
            android:minSdkVersion="10"
            android:targetSdkVersion="15" />
        
        <uses-permission android:name="android.permission.NFC" />
    
        <uses-feature
            android:name="android.hardware.nfc"
            android:required="true" />
    
        <application
            android:allowBackup="true"
            android:icon="@drawable/ic_launcher"
            android:label="@string/app_name"
            android:theme="@style/AppTheme" >
            <activity
                android:name="com.nl.nfcdemo.MainActivity"
                android:label="@string/app_name" >
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
    
                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </activity>
            
        </application>
    
    </manifest>

2、MainAcivity类。

package com.nl.nfcdemo;
    
    import android.app.Activity;
    import android.app.PendingIntent;
    import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    import android.content.IntentFilter;
    import android.content.IntentFilter.MalformedMimeTypeException;
    import android.nfc.NfcAdapter;
    import android.nfc.Tag;
    import android.nfc.tech.MifareClassic;
    import android.nfc.tech.NfcV;
    import android.os.Bundle;
    import android.view.View;
    import android.widget.Button;
    import android.widget.TextView;
    import android.widget.Toast;
    
    public class MainActivity extends Activity {
    
        private final String ACTION_NAME = "android.nfc.action.TECH_DISCOVERED";  
        NfcAdapter nfcAdapter;
        TextView   promt;
        private PendingIntent mPendingIntent;
        private IntentFilter [] mIntentFilters;
        private String[][] mTechLists;
        
        @Override
        public void onCreate(Bundle savedInstanceState){
            super.onCreate (savedInstanceState);
            setContentView (R.layout.activity_main);
            
            promt = (TextView) findViewById (R.id.promt);
             
            // 获取默认的NFC控制器
            nfcAdapter = NfcAdapter.getDefaultAdapter (this);
            if (nfcAdapter == null) {
                promt.setText ("设备不支持NFC！");
                finish ();
                return;
            }
            if (!nfcAdapter.isEnabled ()) {
                promt.setText ("请在系统设置中先启用NFC功能！");
                finish ();
                return;
            }
            
            initNFC();
        }
        
        
        
    
        /**
         *@Description: 初始化
         *@Author:杨攀
         *@Since: 2016年4月27日下午5:38:15
         */
        private void initNFC(){
            //绑定Intent
            Intent mIntent = new Intent (ACTION_NAME);
            mPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
            
            IntentFilter techFilter = new IntentFilter (nfcAdapter.ACTION_TECH_DISCOVERED);
            try {
                techFilter.addDataType ("text/plain");
                mIntentFilters = new IntentFilter[]{techFilter};
            } catch (MalformedMimeTypeException e) {
                e.printStackTrace();
            }
            
            mTechLists  = new String[][] { 
                    new String[] {"android.nfc.tech.NfcA"},
                    new String[]{"android.nfc.tech.NfcB"},
                    new String[]{"android.nfc.tech.NfcF"},
                    new String[]{"android.nfc.tech.NfcV"},
                    new String[]{"android.nfc.tech.Ndef"},
                    new String[]{"android.nfc.tech.NdefFormatable"},
                    new String[]{"android.nfc.tech.IsoDep"},
                    new String[]{"android.nfc.tech.MifareClassic"},
                    new String[]{"android.nfc.tech.MifareUltralight"}
                    };
        }
    
        /**
         *@Description: 拦截系统的 intent, 然后触发读写操作
         *@Author:杨攀
         *@Since: 2016年4月27日下午5:08:20
         *@param intent
         */
        @Override
        protected void onNewIntent(Intent intent){
            super.onNewIntent (intent);
            // 得到是否检测到ACTION_TECH_DISCOVERED触发
            if (NfcAdapter.ACTION_TECH_DISCOVERED.equals (intent.getAction ())) {
                // 处理该intent
                processIntent (intent);
            }
        }
    
    
        /**
         *@Description: 注册 意图 
         *@Author:杨攀
         *@Since: 2016年4月27日下午5:34:21
         */
        @Override
        protected void onResume(){
            super.onResume ();
            nfcAdapter.enableForegroundDispatch (this, mPendingIntent, mIntentFilters, mTechLists);
        }
    
        /**
         *@Description: 窗口关闭的时候，注销意图
         *@Author:杨攀
         *@Since: 2016年4月27日下午5:34:35
         */
        @Override
        protected void onPause(){
            super.onPause ();
            //注销注册
            nfcAdapter.disableForegroundDispatch(this); 
        }
        
        @Override
        protected void onDestroy(){
            super.onDestroy ();
        }
        
        // 字符序列转换为16进制字符串
        private String bytesToHexString(byte[] src){
            StringBuilder stringBuilder = new StringBuilder ("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.forDigit ((src[i] >>> 4) & 0x0F, 16);
                buffer[1] = Character.forDigit (src[i] & 0x0F, 16);
                System.out.println (buffer);
                stringBuilder.append (buffer);
            }
            return stringBuilder.toString ();
        }
    
        /**
         * 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);
            for ( String tech : tagFromIntent.getTechList () ) {
                System.out.println (tech);
            }
            boolean auth = false;
            // 读取TAG
            MifareClassic mfc = MifareClassic.get (tagFromIntent);
            String metaInfo = "本标签的UID为" + Coverter.getUid (intent) + "\n";
            if (mfc != null) {
                try {
                    // Enable I/O operations to the tag from this TagTechnology
                    // object.
                    mfc.connect ();
                    int type = mfc.getType ();// 获取TAG的类型
                    int sectorCount = mfc.getSectorCount ();// 获取TAG中包含的扇区数
                    String typeS = "";
                    switch (type) {
                        case MifareClassic.TYPE_CLASSIC:
                            typeS = "TYPE_CLASSIC";
                            break;
                        case MifareClassic.TYPE_PLUS:
                            typeS = "TYPE_PLUS";
                            break;
                        case MifareClassic.TYPE_PRO:
                            typeS = "TYPE_PRO";
                            break;
                        case MifareClassic.TYPE_UNKNOWN:
                            typeS = "TYPE_UNKNOWN";
                            break;
                    }
                    metaInfo += "卡片类型：" + typeS + "\n共" + sectorCount + "个扇区\n共" + mfc.getBlockCount () + "个块\n存储空间: " + mfc.getSize () + "B\n";
                    for ( int j = 0 ; j < sectorCount ; j++ ) {
                        // Authenticate a sector with key A.
                        auth = mfc.authenticateSectorWithKeyA (j, MifareClassic.KEY_DEFAULT);
                        int bCount;
                        int bIndex;
                        if (auth) {
                            metaInfo += "Sector " + j + ":验证成功\n";
                            // 读取扇区中的块
                            bCount = mfc.getBlockCountInSector (j);
                            bIndex = mfc.sectorToBlock (j);
                            for ( int i = 0 ; i < bCount ; i++ ) {
                                byte[] data = mfc.readBlock (bIndex);
                                metaInfo += "Block " + bIndex + " : " + bytesToHexString (data) + "\n";
                                bIndex++;
                            }
                        } else {
                            metaInfo += "Sector " + j + ":验证失败\n";
                        }
                    }
                } catch (Exception e) {
                    e.printStackTrace ();
                }
            }
            promt.setText (metaInfo);
        }
    
    }

经过运行，可以。我在上传 项目的压缩包。需要的自行下载。

[2cac6c69-e2e1-31a3-a836-229aecb7914f.png]: /images/20220411/527132220dfd468eb2348bb70f85db77.png