NFC(7)向NFC硬件写入数据的两个示例(nfc硬件启动android应用,nfc硬件打开uri)

向NFC标签写入数据基本步骤

1,获取Tag对象

　　Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);

2,判断NFC标签的数据类型（通过Ndef.get方法）

　　Ndef ndef = Ndef.get(tag);

3,NFC开始连接

　　ndef.connect();

4,建NdefMessage数据,然后将它写入数据
　　ndef.writeNdefMessage(ndefMessage); 

示例1: nfc标签设备启动android应用

import android.app.Activity;
import android.app.PendingIntent;
import android.content.Intent;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.Ndef;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class RunApplicationActivity extends Activity {

    private Button mSelectAutoRunApplication;
    private String mPackageName;
    
    
    private NfcAdapter mNfcAdapter;//用来NFC通信
    private PendingIntent mPendingIntent;//用来封装当前窗口

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

        mSelectAutoRunApplication = (Button) findViewById(R.id.button_select_auto_run_application);

        mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
        mPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this,
                getClass()), 0);

    }
    //从另一个aty中取出数据.
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        if (resultCode == 1)
        {
            mSelectAutoRunApplication.setText(data.getExtras().getString(
                    "package_name"));
            String temp = mSelectAutoRunApplication.getText().toString();
            mPackageName = temp.substring(temp.indexOf("\n") + 1);
            
        }

    }
    //由于在manifest.xml中指定当前aty主singleTop,所以startactivity时 onCreate只被调用一次.
    //但是onNewIntent在startactivity会被调用
    @Override
    public void onNewIntent(Intent intent) {
        if (mPackageName == null)
            return;

        //第1步,取得NFC 标签
        Tag detectedTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);

        writeNFCTag(detectedTag);//自写的成员函数
    }

    //第4种 过滤方法的开始函数,要比3种过滤方法优先级高
    @Override
    public void onResume() {
        super.onResume();
        //在Resume时让当前窗口优先处理nfc数据
        if (mNfcAdapter != null){
            mNfcAdapter.enableForegroundDispatch(this, mPendingIntent, null,
                    null);
        }
    }
    //第4种 过滤方法结束函数,要比3种过滤方法优先级高
    @Override
    public void onPause() {
        super.onPause();
        //在onPause时取消让当前窗口优先处理nfc数据
        if (mNfcAdapter != null)
            mNfcAdapter.disableForegroundDispatch(this);
    }
    public void onClick_SelectAutoRunApplication(View view)
    {
        Intent intent = new Intent(this, InstalledApplicationListActivity.class);
        startActivityForResult(intent, 0);
    }
    //向nfc标签写入数据的函数
    public void writeNFCTag(Tag tag) {
        if (tag == null) {
            return;
        }
        try {
            //第2步,判断NFC标签的数据类型（通过Ndef.get方法）
            Ndef ndef = Ndef.get(tag);
            
            if(ndef != null )
            {
                //第3步,NFC开始连接
                ndef.connect();
                
                if(!ndef.isWritable())//标签是否可写.
                {
                    return;
                }
                //第4步,准备数据
                //一个NdefMessage 中可有多个NdefRecord,它们之间关系类似table与record
                NdefMessage ndefMessage = new NdefMessage(
                        new NdefRecord[] { NdefRecord
                                .createApplicationRecord(mPackageName) });
                int size = ndefMessage.toByteArray().length;
                if(ndef.getMaxSize() < size)
                {
                    return;
                }
                //第5步,把数据写入到nfc标签中.
                ndef.writeNdefMessage(ndefMessage);
                //第6步,写入成功提示
                Toast.makeText(this, "ok", Toast.LENGTH_LONG).show();
            }
        } catch (Exception e) {
            //有可能异常
            e.printStackTrace();
        }
    }
}

 

manifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="c.e.run.application"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="15"
        android:targetSdkVersion="15" />

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

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".RunApplicationActivity"
            android:label="@string/title_activity_auto_run_application"
            android:launchMode="singleTop"
            android:screenOrientation="portrait" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".InstalledApplicationListActivity"
            android:label="@string/title_activity_installed_application_list"
            android:screenOrientation="portrait" />

    </application>

</manifest>

 

示例2: nfc标签设备打开一个uri

import android.app.Activity;
import android.app.PendingIntent;
import android.content.Intent;
import android.net.Uri;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.Ndef;
import android.nfc.tech.NdefFormatable;
import android.os.Bundle;
import android.widget.Toast;

public class AutoOpenUriActivity extends Activity {
    private NfcAdapter nfcAdapter;
    private PendingIntent pendingIntent;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_auto_open_uri);
        nfcAdapter = NfcAdapter.getDefaultAdapter(this);
        pendingIntent = PendingIntent.getActivity(this, 0, new Intent(this,
                getClass()), 0);

    }

    @Override
    public void onResume() {
        super.onResume();
        if (nfcAdapter != null)
            nfcAdapter
                    .enableForegroundDispatch(this, pendingIntent, null, null);
    }

    @Override
    public void onNewIntent(Intent intent) {
        //第1步,取得NFC 标签
        Tag detectedTag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
        writeNFCTag(detectedTag);
    }

    @Override
    public void onPause() {
        super.onPause();
        if (nfcAdapter != null)
            nfcAdapter.disableForegroundDispatch(this);

    }

    public void writeNFCTag(Tag tag) {
        if (tag == null) {
            return;
        }
        Uri uri = Uri.parse("http://www.bing.com");
        NdefMessage ndefMessage = new NdefMessage(
                new NdefRecord[] { NdefRecord.createUri(uri) });
        int size = ndefMessage.toByteArray().length;
        try{
            Ndef ndef = Ndef.get(tag);
            
            if (ndef != null){// 已经格式化
                ndef.connect();
                if (!ndef.isWritable()) {
                    return;
                }
                if (ndef.getMaxSize() < size) {
                    return;
                }
                ndef.writeNdefMessage(ndefMessage);
                Toast.makeText(this, "ok", Toast.LENGTH_LONG).show();
            } else {// 标签未格式化
                    // 第1步,获取NdefFormatable
                NdefFormatable format = NdefFormatable.get(tag);
                if (format != null){// 可以格式化
                    // 第2步,连接
                    format.connect();
                    // 第3步,格式化同时把数据写入到标签中.
                    format.format(ndefMessage);
                    Toast.makeText(this, "ok", Toast.LENGTH_LONG).show();
                } else {// 不可格式化
                    Toast.makeText(this, "formating is failed",
                            Toast.LENGTH_LONG).show();
                }
            }
            
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}