Question

我是新的开发者android。如何在onCreate主要活动中使用此代码当我触摸NFC标签读取数据时。我使用流动代码读取标签，如何更改它来解决问题？

in manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="example.Ultralight"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-permission android:name="android.permission.NFC" /> 
    <uses-sdk android:minSdkVersion="10" /> 
    <uses-feature android:name="android.hardware.nfc" android:required="true" />

    <application android:icon="@drawable/icon" android:label="@string/app_name" android:debuggable="true">
        <activity android:name="MainView"
                  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.TECH_DISCOVERED"/> 
            </intent-filter>
                <meta-data android:name="android.nfc.action.TECH_DISCOVERED"
                android:resource="@xml/tech_filter"/> 
        </activity>

    </application>
</manifest>

Answer 1

如果您希望应用仅在应用启动时对标记执行操作，则需要在OnCreate中设置一个意图过滤器并对其进行操作。这样的事情。

更新：添加了代码。

NfcAdapter mAdapter;
private PendingIntent mPendingIntent;
private IntentFilter[] mFilters;
private String[][] mTechLists;

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

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

    IntentFilter ntech2 = new IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED);
    IntentFilter ntech3 = new IntentFilter(NfcAdapter.ACTION_TECH_DISCOVERED);

    mFilters = new IntentFilter[] {
            ntech3, ntech2,
    };

    mTechLists = new String[][] { new String[] { 
            NfcA.class.getName(), 
            Ndef.class.getName() } };

    Intent intent = getIntent();
    resolveIntent (intent);

} 

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    resolveIntent(intent);   
}

private void resolveIntent (Intent intent)
{
    String action = intent.getAction();
    if ((NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) || 
            (NfcAdapter.ACTION_TECH_DISCOVERED.equals(action)))
    {
        Tag tagFromIntent = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);

        Parcelable[] rawMsgs = intent
                .getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
        NdefMessage msg = (NdefMessage) rawMsgs[0];

        extractMessage(msg);

    }
}

private void extractMessage(NdefMessage msg) {
    byte[] array = null;
    array = msg.getRecords()[0].getPayload();
    String displaystring = convert (array);

    TextView tv = (TextView) findViewById(R.id.txt_DisplayData);
    tv.setText(displaystring);
}

String convert(byte[] data) {
    StringBuilder sb = new StringBuilder(data.length);
    for (int i = 0; i < data.length; ++ i) {
        if (data[i] < 0) throw new IllegalArgumentException();
        sb.append((char) data[i]);
    }
    return sb.toString();
}

如何使用NFC标签ACTIONTEC DISCOVERED主要活动？

1 个答案: