12、NFC技术：读写NFC标签中的Uri数据

功能实现，如下代码所示：

读写NFC标签的Uri 主Activity

 

import cn.read.write.uri.library.UriRecord;
import android.app.Activity;
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.TextView;
import android.widget.Toast;

/**
 * 读写NFC标签的Uri
 * @author dr
 *
 */
public class ReadWriteUriMainActivity extends Activity {
    private TextView mSelectUri;
    private String mUri;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_read_write_uri_main);
        mSelectUri = (TextView) findViewById(R.id.textview_uri);
    }

    public void onClick_SelectUri(View view) {
        Intent intent = new Intent(this, UriListActivity.class);
        startActivityForResult(intent, 1);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == 1 && resultCode == 1) {
            mUri = data.getStringExtra("uri");
            mSelectUri.setText(mUri);
        }
    }

    public void onNewIntent(Intent intent) {
        if (mUri == null) {
            Intent myIntent = new Intent(this, ShowNFCTagContentActivity.class);
            myIntent.putExtras(intent);
            myIntent.setAction(NfcAdapter.ACTION_NDEF_DISCOVERED);
            startActivity(myIntent);
        } else {  // write nfc
            Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
            NdefMessage ndefMessage = new NdefMessage(
                    new NdefRecord[] { createUriRecord(mUri) });
            if (writeTag(ndefMessage, tag)) {
                mUri = null;
                mSelectUri.setText("");
            }
        }
    }

    public NdefRecord createUriRecord(String uriStr) {
        byte prefix = 0;
        for (Byte b : UriRecord.URI_PREFIX_MAP.keySet()) {
            String prefixStr = UriRecord.URI_PREFIX_MAP.get(b).toLowerCase();
            if ("".equals(prefixStr))
                continue;
            if (uriStr.toLowerCase().startsWith(prefixStr)) {
                prefix = b;
                uriStr = uriStr.substring(prefixStr.length());
                break;
            }
        }
        byte[] data = new byte[1 + uriStr.length()];
        data[0] = prefix;
        System.arraycopy(uriStr.getBytes(), 0, data, 1, uriStr.length());

        NdefRecord record = new NdefRecord(NdefRecord.TNF_WELL_KNOWN,
                NdefRecord.RTD_URI, new byte[0], data);
        return record;
    }

    boolean writeTag(NdefMessage message, Tag tag) {
        int size = message.toByteArray().length;
        try {
            Ndef ndef = Ndef.get(tag);
            if (ndef != null) {
                ndef.connect();
                if (!ndef.isWritable()) {
                    return false;
                }
                if (ndef.getMaxSize() < size) {
                    return false;
                }
                ndef.writeNdefMessage(message);
                Toast.makeText(this, "ok", Toast.LENGTH_LONG).show();
                return true;
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
        return false;
    }
}

 

 

读写NFC标签的Uri 主xml

 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="onClick_SelectUri"
        android:text="选择Uri" />

    <TextView
        android:id="@+id/textview_uri"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="16sp" />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp"
        android:text="请将NFC标签靠近手机背面读取或写入Uri"
        android:textColor="#F00"
        android:textSize="16sp" />

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:src="@drawable/read_nfc_tag" />

</LinearLayout>

 

 

显示URI列表Activity

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;

/**
 * 显示URI列表
 * @author dr
 *
 */
public class UriListActivity extends ListActivity implements
        OnItemClickListener {
    private String uris[] = new String[] { "http://www.google.com",
            "http://www.apple.com", "http://developer.apple.com",
            "http://www.126.com", "ftp://192.168.17.160",
            "https://192.168.17.120", "smb://192.168.17.100" };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, android.R.id.text1, uris);
        setListAdapter(arrayAdapter);
        getListView().setOnItemClickListener(this);
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
            long id) {
        Intent intent = new Intent();
        intent.putExtra("uri", uris[position]);
        setResult(1, intent);
        finish();
    }

}

显示NFC标签内容Activity

import android.app.Activity;
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.os.Parcelable;
import android.widget.TextView;
import cn.read.write.uri.library.UriRecord;

/**
 * 显示NFC标签内容
 * @author dr
 *
 */
public class ShowNFCTagContentActivity extends Activity {
    private TextView mTagContent;
    private Tag mDetectedTag;
    private String mTagText;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_show_nfctag_content);
        mTagContent = (TextView) findViewById(R.id.textview_tag_content);
        mDetectedTag = getIntent().getParcelableExtra(NfcAdapter.EXTRA_TAG);
        Ndef ndef = Ndef.get(mDetectedTag);
        mTagText = ndef.getType() + "
 max size:" + ndef.getMaxSize()
                + " bytes

";

        readNFCTag();

        mTagContent.setText(mTagText);
    }

    private void readNFCTag() {
        if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(getIntent().getAction())) {
            Parcelable[] rawMsgs = getIntent().getParcelableArrayExtra(
                    NfcAdapter.EXTRA_NDEF_MESSAGES);

            NdefMessage ndefMessage = null;

            int contentSize = 0;
            if (rawMsgs != null) {
                if (rawMsgs.length > 0) {
                    ndefMessage = (NdefMessage) rawMsgs[0];
                    contentSize = ndefMessage.toByteArray().length;
                } else {
                    return;
                }
            }
            try {
                NdefRecord ndefRecord = ndefMessage.getRecords()[0];
                UriRecord uriRecord = UriRecord.parse(ndefRecord);
                mTagText += uriRecord.getUri().toString() + "

Uri
"
                        + contentSize + " bytes";
            } catch (Exception e) {
                // TODO: handle exception
            }
        }
    }

}

显示NFC标签内容xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textview_tag_content"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="6dp"
        android:textSize="16sp" />

</LinearLayout>

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="cn.eoe.read.write.uri"
    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=".ReadWriteUriMainActivity"
            android:label="读写NFC标签的Uri"
            android:launchMode="singleTask" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.nfc.action.NDEF_DISCOVERED" />

                <category android:name="android.intent.category.DEFAULT" />

                <data android:scheme="http" />
                <data android:scheme="https" />
                <data android:scheme="ftp" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.nfc.action.NDEF_DISCOVERED" />

                <category android:name="android.intent.category.DEFAULT" />
                <data android:mimeType="text/plain" />
            </intent-filter>
        </activity>
        <activity
            android:name="cn.eoe.read.write.uri.ShowNFCTagContentActivity"
            android:label="显示NFC标签内容" />
        <activity
            android:name="cn.eoe.read.write.uri.UriListActivity"
            android:label="选择Uri" />
    </application>

</manifest>

DEMO下载地址：http://download.csdn.net/detail/androidsj/7680247