Question

我正在创建一个nfc阅读器我按照教程进行操作，效果很好结果将显示nfc标记中的值，例如;文本视图中的123456 如何更改结果以放入Editview？
我已经尝试但仍然没有运气 MainActivity.java

package net.vrallev.android.nfc.demo;

import java.io.UnsupportedEncodingException;
import java.util.Arrays;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.IntentFilter.MalformedMimeTypeException;
import android.nfc.NdefMessage;
import android.nfc.NdefRecord;
import android.nfc.NfcAdapter;
import android.nfc.Tag;
import android.nfc.tech.Ndef;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
import android.widget.Toast;

/**
* Activity for reading data from an NDEF Tag.
* 
* @author Ralf Wondratschek
*
*/
public class MainActivity extends Activity {

public static final String MIME_TEXT_PLAIN = "text/plain";
public static final String TAG = "NfcDemo";

private TextView mTextView;
private NfcAdapter mNfcAdapter;

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

    mTextView = (TextView) findViewById(R.id.textView_explanation);

    mNfcAdapter = NfcAdapter.getDefaultAdapter(this);

    if (mNfcAdapter == null) {
        // Stop here, we definitely need NFC
        Toast.makeText(this, "This device doesn't support NFC.", Toast.LENGTH_LONG).show();
        finish();
        return;

    }

    if (!mNfcAdapter.isEnabled()) {
        mTextView.setText("NFC is disabled.");
    } else {
        mTextView.setText(R.string.explanation);
    }

    handleIntent(getIntent());
}

@Override
protected void onResume() {
    super.onResume();

    /*
     * It's important, that the activity is in the foreground (resumed). Otherwise
     * an IllegalStateException is thrown. 
     */
    setupForegroundDispatch(this, mNfcAdapter);
}

@Override
protected void onPause() {
    /*
     * Call this before onPause, otherwise an IllegalArgumentException is thrown as well.
     */
    stopForegroundDispatch(this, mNfcAdapter);

    super.onPause();
}

@Override
protected void onNewIntent(Intent intent) {
    /*
     * This method gets called, when a new Intent gets associated with the current activity     instance.
     * Instead of creating a new activity, onNewIntent will be called. For more information have   a look
     * at the documentation.
     * 
     * In our case this method gets called, when the user attaches a Tag to the device.
     */
    handleIntent(intent);
}

private void handleIntent(Intent intent) {
    String action = intent.getAction();
    if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) {

        String type = intent.getType();
        if (MIME_TEXT_PLAIN.equals(type)) {

            Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
            new NdefReaderTask().execute(tag);

        } else {
            Log.d(TAG, "Wrong mime type: " + type);
        }
    } else if (NfcAdapter.ACTION_TECH_DISCOVERED.equals(action)) {

        // In case we would still use the Tech Discovered Intent
        Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
        String[] techList = tag.getTechList();
        String searchedTech = Ndef.class.getName();

        for (String tech : techList) {
            if (searchedTech.equals(tech)) {
                new NdefReaderTask().execute(tag);
                break;
            }
        }
    }
}

/**
 * @param activity The corresponding {@link Activity} requesting the foreground dispatch.
 * @param adapter The {@link NfcAdapter} used for the foreground dispatch.
 */
public static void setupForegroundDispatch(final Activity activity, NfcAdapter adapter) {
    final Intent intent = new Intent(activity.getApplicationContext(), activity.getClass());
    intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);

    final PendingIntent pendingIntent = PendingIntent.getActivity(activity.getApplicationContext(), 0, intent, 0);

    IntentFilter[] filters = new IntentFilter[1];
    String[][] techList = new String[][]{};

    // Notice that this is the same filter as in our manifest.
    filters[0] = new IntentFilter();
    filters[0].addAction(NfcAdapter.ACTION_NDEF_DISCOVERED);
    filters[0].addCategory(Intent.CATEGORY_DEFAULT);
    try {
        filters[0].addDataType(MIME_TEXT_PLAIN);
    } catch (MalformedMimeTypeException e) {
        throw new RuntimeException("Check your mime type.");
    }

    adapter.enableForegroundDispatch(activity, pendingIntent, filters, techList);
}

/**
 * @param activity The corresponding {@link BaseActivity} requesting to stop the foreground dispatch.
 * @param adapter The {@link NfcAdapter} used for the foreground dispatch.
 */
public static void stopForegroundDispatch(final Activity activity, NfcAdapter adapter) {
    adapter.disableForegroundDispatch(activity);
}

/**
 * Background task for reading the data. Do not block the UI thread while reading. 
 * 
 * @author Ralf Wondratschek
 *
 */
private class NdefReaderTask extends AsyncTask<Tag, Void, String> {

    @Override
    protected String doInBackground(Tag... params) {
        Tag tag = params[0];

        Ndef ndef = Ndef.get(tag);
        if (ndef == null) {
            // NDEF is not supported by this Tag. 
            return null;
        }

        NdefMessage ndefMessage = ndef.getCachedNdefMessage();

        NdefRecord[] records = ndefMessage.getRecords();
        for (NdefRecord ndefRecord : records) {
            if (ndefRecord.getTnf() == NdefRecord.TNF_WELL_KNOWN && Arrays.equals(ndefRecord.getType(), NdefRecord.RTD_TEXT)) {
                try {
                    return readText(ndefRecord);
                } catch (UnsupportedEncodingException e) {
                    Log.e(TAG, "Unsupported Encoding", e);
                }
            }
        }

        return null;
    }

    private String readText(NdefRecord record) throws UnsupportedEncodingException {
        /*
         * See NFC forum specification for "Text Record Type Definition" at 3.2.1 
         * 
         * http://www.nfc-forum.org/specs/
         * 
         * bit_7 defines encoding
         * bit_6 reserved for future use, must be 0
         * bit_5..0 length of IANA language code
         */

        byte[] payload = record.getPayload();

        // Get the Text Encoding
        String textEncoding = ((payload[0] & 128) == 0) ? "UTF-8" : "UTF-16";

        // Get the Language Code
        int languageCodeLength = payload[0] & 0063;

        // String languageCode = new String(payload, 1, languageCodeLength, "US-ASCII");
        // e.g. "en"

        // Get the Text
        return new String(payload, languageCodeLength + 1, payload.length - languageCodeLength - 1, textEncoding);
    }

    @Override
    protected void onPostExecute(String result) {
        if (result != null) {
            mTextView.setText("Read content: " + result);
        }
    }
}
}

activity_main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<TextView
    android:id="@+id/textView_explanation"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/explanation" />

</RelativeLayout>

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="net.vrallev.android.nfc.demo"
android:versionCode="1"
android:versionName="1.0" >

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

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

<uses-sdk
    android:minSdkVersion="10"
    android:targetSdkVersion="17" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="net.vrallev.android.nfc.demo.MainActivity"
        android:label="@string/app_name" >
        <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:mimeType="text/plain" />
        </intent-filter>
    </activity>
</application>

</manifest>

Answer 1

您需要将解释字段声明为XML中的EditText的唯一更改：

<EditText
    android:id="@+id/textView_explanation"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/explanation" />

由于EditText是TextView的子类，因此您甚至不需要修改代码，除非您想要调用仅在EditText中的函数。

这是你遇到的问题，还是我误解了？

Answer 2

在您的布局中添加EditText：

<EditText
    android:id="@+id/editText1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

现在将此代码添加到MainActivity类：

...

public class MainActivity extends Activity {

public static final String MIME_TEXT_PLAIN = "text/plain";
public static final String TAG = "NfcDemo";

private TextView mTextView;
private NfcAdapter mNfcAdapter;
private EditText mEditText;

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

    mTextView = (TextView) findViewById(R.id.textView_explanation);
    mEditText = (EditText) findViewById(R.id.editText1);

    //Set Text View value in Edit Text
    mEditText.setText(mTextView.getText().toString());

    ...
}


...

将Textview值放入Edittext

2 个答案: