Android NFC：只发送一个活动，接收一个活动

我希望我的ActivityNFCSender通过NFC向我的ActivityNFCrecever发送一个整数。下面的代码可以工作。但有一个问题：当建立连接时，两个活动都会显示发送提示！但是我只希望第一个能够发送（一个整数）并显示提示。怎么做

活动NFCSender：

public class ActivityNFCSender extends ActivityBase {

public static final String EXTRA_RES_ID = "res_id";

private NfcAdapter mNfcAdapter;
private int mReservServerId;


@Override
public void onCreate(Bundle savedInstanceState) {
    setContentView(R.layout.activity_nfc);
    super.onCreate(savedInstanceState);

    mReservServerId = getIntent().getIntExtra(EXTRA_RES_ID, 0);
}


public void onResume(){
    super.onResume();   

    mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
    if(mNfcAdapter == null){
        messageDialogQuit(R.string.error_no_nfc);
    }
    else if(!mNfcAdapter.isEnabled()){
        new AlertDialog.Builder(this).setCancelable(true).setMessage(R.string.error_nfc_off)
            .setPositiveButton(R.string.turn_on, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.dismiss();
                        Intent settingsIntent = new Intent(Settings.ACTION_SETTINGS);
                        startActivity(settingsIntent);                          
                    }
                })
            .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.dismiss();    
                        finish();
                    }
                })                  
            .create().show();
    }
    else{           
        //Set sending
        mNfcAdapter.enableForegroundNdefPush(ActivityNFCSender.this,  getIntAsNdef(mReservServerId));
    }
}

public void onPause(){      
    if(mNfcAdapter != null && mNfcAdapter.isEnabled()){
        mNfcAdapter.disableForegroundNdefPush(this);
    }
    super.onPause();        
}


private NdefMessage getIntAsNdef(int pInt) {
    byte[] textBytes = (pInt+"").getBytes(Charset.forName("UTF8"));
    NdefRecord textRecord = new NdefRecord(NdefRecord.TNF_MIME_MEDIA, "text/plain".getBytes(), new byte[] {}, textBytes);
    return new NdefMessage(new NdefRecord[] {
        textRecord
    });
}

public class ActivityNFCReceiver extends ActivityBase {

private NfcAdapter mNfcAdapter;
private PendingIntent mNfcPendingIntent;
private IntentFilter[] mNdefExchangeFilters;    


@Override
public void onCreate(Bundle savedInstanceState) {
    setContentView(R.layout.activity_nfc);
    super.onCreate(savedInstanceState);

    ((TextView) findViewById(R.id.nfcTVStatus)).setText(R.string.receiving);
}


public void onResume(){
    super.onResume();   

    mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
    if(mNfcAdapter == null){
        messageDialogQuit(R.string.error_no_nfc);
    }
    else if(!mNfcAdapter.isEnabled()){
        new AlertDialog.Builder(this).setCancelable(true).setMessage(R.string.error_nfc_off)
            .setPositiveButton(R.string.turn_on, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.dismiss();
                        Intent settingsIntent = new Intent(Settings.ACTION_SETTINGS);
                        startActivity(settingsIntent);                          
                    }
                })
            .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.dismiss();    
                        finish();
                    }
                })                  
            .create().show();
    }
    else{           
        mNfcPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
        // Intent filters for exchanging over p2p.
        IntentFilter ndefDetected = new IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED);
        try {
            ndefDetected.addDataType("text/plain");
        } 
        catch (MalformedMimeTypeException e) {
            e.printStackTrace();
        }

        mNdefExchangeFilters = new IntentFilter[] { ndefDetected };

        //set receiving
        mNfcAdapter.enableForegroundDispatch(ActivityNFCReceiver.this, mNfcPendingIntent, mNdefExchangeFilters, null);
    }
}

public void onPause(){      
    if(mNfcAdapter != null && mNfcAdapter.isEnabled()){
        mNfcAdapter.disableForegroundDispatch(ActivityNFCReceiver.this);
    }
    super.onPause();        
}


@Override
protected void onNewIntent(Intent intent) {
    if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(intent.getAction())) {
        NdefMessage[] msgs = getNdefMessages(intent);
        if(msgs.length > 0){
            try{
                NdefRecord firstRecord = msgs[0].getRecords()[0];
                byte[] payload = firstRecord.getPayload();
                String str = new String(payload, Charset.forName("UTF8"));

                int reservServerId = Integer.parseInt(str);
                returnResult(reservServerId);
            }
            catch(Exception e){
                messageDialog(R.string.error_during_NFC);
            }
        }
    }
}


public void onCancelClicked(View pV){
    finish();
}

private NdefMessage[] getNdefMessages(Intent intent) {
    // Parse the intent
    NdefMessage[] msgs = null;
    String action = intent.getAction();
    if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(action) || NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) {
        Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
        if (rawMsgs != null) {
            msgs = new NdefMessage[rawMsgs.length];
            for (int i = 0; i < rawMsgs.length; i++) {
                msgs[i] = (NdefMessage) rawMsgs[i];
            }
        }
        else {
            // Unknown tag type
            byte[] empty = new byte[] {};
            NdefRecord record = new NdefRecord(NdefRecord.TNF_UNKNOWN, empty, empty, empty);
            NdefMessage msg = new NdefMessage(new NdefRecord[] { record });
            msgs = new NdefMessage[] { msg };
        }
    }
    else {
        Log.d(TAG, "Unknown intent.");
        finish();
    }
    return msgs;
}


private void returnResult(int pResServerId){
    Intent result = new Intent();
    result.putExtra(ActivityCompanySubMenu.EXTRA_RES_SERVER_ID, pResServerId);
    setResult(RESULT_OK, result);
    finish();
}

活动收信人：

public class ActivityNFCSender extends ActivityBase {

public static final String EXTRA_RES_ID = "res_id";

private NfcAdapter mNfcAdapter;
private int mReservServerId;


@Override
public void onCreate(Bundle savedInstanceState) {
    setContentView(R.layout.activity_nfc);
    super.onCreate(savedInstanceState);

    mReservServerId = getIntent().getIntExtra(EXTRA_RES_ID, 0);
}


public void onResume(){
    super.onResume();   

    mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
    if(mNfcAdapter == null){
        messageDialogQuit(R.string.error_no_nfc);
    }
    else if(!mNfcAdapter.isEnabled()){
        new AlertDialog.Builder(this).setCancelable(true).setMessage(R.string.error_nfc_off)
            .setPositiveButton(R.string.turn_on, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.dismiss();
                        Intent settingsIntent = new Intent(Settings.ACTION_SETTINGS);
                        startActivity(settingsIntent);                          
                    }
                })
            .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.dismiss();    
                        finish();
                    }
                })                  
            .create().show();
    }
    else{           
        //Set sending
        mNfcAdapter.enableForegroundNdefPush(ActivityNFCSender.this,  getIntAsNdef(mReservServerId));
    }
}

public void onPause(){      
    if(mNfcAdapter != null && mNfcAdapter.isEnabled()){
        mNfcAdapter.disableForegroundNdefPush(this);
    }
    super.onPause();        
}


private NdefMessage getIntAsNdef(int pInt) {
    byte[] textBytes = (pInt+"").getBytes(Charset.forName("UTF8"));
    NdefRecord textRecord = new NdefRecord(NdefRecord.TNF_MIME_MEDIA, "text/plain".getBytes(), new byte[] {}, textBytes);
    return new NdefMessage(new NdefRecord[] {
        textRecord
    });
}

public class ActivityNFCReceiver extends ActivityBase {

private NfcAdapter mNfcAdapter;
private PendingIntent mNfcPendingIntent;
private IntentFilter[] mNdefExchangeFilters;    


@Override
public void onCreate(Bundle savedInstanceState) {
    setContentView(R.layout.activity_nfc);
    super.onCreate(savedInstanceState);

    ((TextView) findViewById(R.id.nfcTVStatus)).setText(R.string.receiving);
}


public void onResume(){
    super.onResume();   

    mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
    if(mNfcAdapter == null){
        messageDialogQuit(R.string.error_no_nfc);
    }
    else if(!mNfcAdapter.isEnabled()){
        new AlertDialog.Builder(this).setCancelable(true).setMessage(R.string.error_nfc_off)
            .setPositiveButton(R.string.turn_on, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.dismiss();
                        Intent settingsIntent = new Intent(Settings.ACTION_SETTINGS);
                        startActivity(settingsIntent);                          
                    }
                })
            .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.dismiss();    
                        finish();
                    }
                })                  
            .create().show();
    }
    else{           
        mNfcPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);
        // Intent filters for exchanging over p2p.
        IntentFilter ndefDetected = new IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED);
        try {
            ndefDetected.addDataType("text/plain");
        } 
        catch (MalformedMimeTypeException e) {
            e.printStackTrace();
        }

        mNdefExchangeFilters = new IntentFilter[] { ndefDetected };

        //set receiving
        mNfcAdapter.enableForegroundDispatch(ActivityNFCReceiver.this, mNfcPendingIntent, mNdefExchangeFilters, null);
    }
}

public void onPause(){      
    if(mNfcAdapter != null && mNfcAdapter.isEnabled()){
        mNfcAdapter.disableForegroundDispatch(ActivityNFCReceiver.this);
    }
    super.onPause();        
}


@Override
protected void onNewIntent(Intent intent) {
    if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(intent.getAction())) {
        NdefMessage[] msgs = getNdefMessages(intent);
        if(msgs.length > 0){
            try{
                NdefRecord firstRecord = msgs[0].getRecords()[0];
                byte[] payload = firstRecord.getPayload();
                String str = new String(payload, Charset.forName("UTF8"));

                int reservServerId = Integer.parseInt(str);
                returnResult(reservServerId);
            }
            catch(Exception e){
                messageDialog(R.string.error_during_NFC);
            }
        }
    }
}


public void onCancelClicked(View pV){
    finish();
}

private NdefMessage[] getNdefMessages(Intent intent) {
    // Parse the intent
    NdefMessage[] msgs = null;
    String action = intent.getAction();
    if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(action) || NfcAdapter.ACTION_NDEF_DISCOVERED.equals(action)) {
        Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
        if (rawMsgs != null) {
            msgs = new NdefMessage[rawMsgs.length];
            for (int i = 0; i < rawMsgs.length; i++) {
                msgs[i] = (NdefMessage) rawMsgs[i];
            }
        }
        else {
            // Unknown tag type
            byte[] empty = new byte[] {};
            NdefRecord record = new NdefRecord(NdefRecord.TNF_UNKNOWN, empty, empty, empty);
            NdefMessage msg = new NdefMessage(new NdefRecord[] { record });
            msgs = new NdefMessage[] { msg };
        }
    }
    else {
        Log.d(TAG, "Unknown intent.");
        finish();
    }
    return msgs;
}


private void returnResult(int pResServerId){
    Intent result = new Intent();
    result.putExtra(ActivityCompanySubMenu.EXTRA_RES_SERVER_ID, pResServerId);
    setResult(RESULT_OK, result);
    finish();
}

公共类ActivityNFCReceiver扩展ActivityBase{
专用NfcAdapter mNfcAdapter；
私人挂件MNFCpendingent；
私有IntentFilter[]MNDEFExchangeFilter；
@凌驾
创建时的公共void（Bundle savedInstanceState）{
setContentView（R.layout.activity\u nfc）；
super.onCreate（savedInstanceState）；
（（TextView）findviewbyd（R.id.nfcTVStatus））.setText（R.string.receiving）；
}
恢复时公开作废（）{
super.onResume（）；
mNfcAdapter=NfcAdapter.getDefaultAdapter（此）；
if（mNfcAdapter==null）{
messageDialogQuit（R.string.error\u no\u nfc）；
}
如果（！mNfcAdapter.isEnabled（）），则为else{
新建AlertDialog.Builder（this）.setCancelable（true）.setMessage（R.string.error\u nfc\u off）
.setPositiveButton（R.string.turn_打开，新的DialogInterface.OnClickListener（）{
public void onClick（DialogInterface对话框，int-id）{
dialog.dismise（）；
意向设置Intent=新意向（设置、操作和设置）；
启动触觉（设置输入）；
}
})
.setNegativeButton（R.string.cancel，新建DialogInterface.OnClickListener（）{
public void onClick（DialogInterface对话框，int-id）{
dialog.dismise（）；
完成（）；
}
})                  
.create（）.show（）；
}
否则{
mNfcPendingIntent=PendingIntent.getActivity（this，0，newintent（this，getClass（））.addFlags（Intent.FLAG\u ACTIVITY\u SINGLE\u TOP），0）；
//用于通过p2p交换的意图过滤器。
IntentFilter ndefDetected=新的IntentFilter（NfcAdapter.ACTION\u NDEF\u DISCOVERED）；
试一试{
ndefDetected.addDataType（“文本/普通”）；
} 
捕获（格式错误的dmimetype异常）{
e、 printStackTrace（）；
}
mNdefExchangeFilters=新的IntentFilter[]{ndefDetected}；
//设置接收
mNfcAdapter.enableForegroundDispatch（ActivityNFCReceiver.this，mnfcpendingent，mndefchangefilters，null）；
}
}
public void onPause（）{
if（mNfcAdapter！=null&&mNfcAdapter.isEnabled（））{
mNfcAdapter.disableForegroundDispatch（ActivityNFCReceiver.this）；
}
super.onPause（）；
}
@凌驾
受保护的void onNewIntent（意图）{
if（NfcAdapter.ACTION\u NDEF\u DISCOVERED.equals（intent.getAction（）））{
NdefMessage[]msgs=获取NDEFMessages（意图）；
如果（msgs.length>0）{
试一试{
NdefRecord firstRecord=msgs[0].getRecords（）[0]；
字节[]有效载荷=firstRecord.getPayload（）；
String str=新字符串（有效负载，Charset.forName（“UTF8”）；
int reservServerId=Integer.parseInt（str）；
returnResult（reservServerId）；
}
捕获（例外e）{
messageDialog（R.string.error\u在NFC期间）；
}
}
}
}
单击“取消”后的公共无效（查看pV）{
完成（）；
}
私有NdefMessage[]获取NDEFMessages（意图）{
//解析意图
NdefMessage[]msgs=null；
String action=intent.getAction（）；
if（NfcAdapter.ACTION_TAG_DISCOVERED.equals（ACTION）| NfcAdapter.ACTION_NDEF_DISCOVERED.equals（ACTION））{
Parcelable[]rawMsgs=intent.getParcelableArrayExtra（NfcAdapter.EXTRA\u NDEF\u消息）；
if（rawMsgs！=null）{
msgs=新的NdefMessage[rawMsgs.length]；
对于（int i=0；i

---

}

您可以使用

NfcAdapter.setNdefPushMessage

方法禁用特定活动（即您的

活动nfcreceiver

）的Beam UI：

public void onCreate(Bundle savedInstanceState) {

    [...]

    mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
    if (mNfcAdapter != null) {
        mNfcAdapter.setNdefPushMessage(null, this);
    }
}

请注意，

enableforegroundendefpush

方法自Android 4.0（API级别14）以来就被弃用，并且几乎所有支持NFC的Android设备都使用Android 4.0或更高版本

---

在禁用Beam UI时，这种方式适用于Nexus设备，并且是官方记录的方式（请参阅）：

如果使用空NDEF消息[…]调用setNdefPushMessage（…），则指定活动的NDEF推送将被完全禁用。这也会禁用Android操作系统为这些活动以其他方式代表您发送的任何默认NDEF消息

---

不幸的是，这似乎不适用于某些Android设备的NFC实现。例如，它在运行Android 4.3的三星Galaxy S3上不起作用。

我更改了代码并添加了mNfcAdapter.setNdefPushMessage（null，this）；紧接着mNfcAdapter.enableForegroundDispatch（ActivityNFCReceiver.this、mnfcpendingent、mndefchangefilters、null）；在receiver活动中，但结果相同：两个设备都显示发送提示。我可能错了，但是