如何让android广播接收器在后台工作？

如何解决如何让android广播接收器在后台工作？

实际上，我正在开发一项功能，我想将每条传入的消息转发到我的设备，转发到另一个号码。但问题是，当应用程序运行时，它会前进，但是当我从最近的应用程序中将其滑出时。那么它不会。

Android 清单权限

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

我的清单中的接收器

<receiver
    android:name=".SMSForwarder"
    android:permission="android.permission.BROADCAST_SMS"
    android:enabled="true"
    android:exported="true">
    <intent-filter>
        <action android:name="android.provider.Telephony.SMS_RECEIVED"/>
    </intent-filter>
</receiver>

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private static final int MY_PERMISSIONS_REQUEST_SEND_SMS = 1;

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

        if (!checkForSmsPermission()) {
            requestPermission();
        }


        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.P) {
            RoleManager roleManager = getSystemService(RoleManager.class);
            startActivityForResult(roleManager.createRequestRoleIntent(RoleManager.ROLE_SMS),12);
        } else {
            Intent intent = new  Intent(Telephony.Sms.Intents.ACTION_CHANGE_DEFAULT);
            intent.putExtra(Telephony.Sms.Intents.EXTRA_PACKAGE_NAME,getPackageName());
            startActivity(intent);
        }
    }

    /**
     * This method checks for permission for SMS
     * @return true/false
     */
    private boolean checkForSmsPermission() {
        if (ActivityCompat.checkSelfPermission(this,Manifest.permission.SEND_SMS) !=
                PackageManager.PERMISSION_GRANTED) {
            Log.d("warning","Permission not granted");
            return false;
        } else {
            Log.d("warning","Permission granted");
            return true;
        }
    }

    /**
     *This method requests permission for SMS
     */
    private void requestPermission() {
        ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.SEND_SMS},MY_PERMISSIONS_REQUEST_SEND_SMS);
    }
}

SMSForwader.java

public class SMSForwarder extends BroadcastReceiver {

    @Override
    public void onReceive(Context context,Intent intent) {
        if (intent.getAction().equals(Telephony.Sms.Intents.SMS_RECEIVED_ACTION)) {

            Intent service = new Intent(context,MyBrodcastRecieverService.class);
            context.startService(service);
            String number = "[phone]"; // number,where msgs will be forwarded.

            Bundle bundle = intent.getExtras();
            if (bundle.containsKey("pdus")) {

                // here we build a dict where keys are message senders
                // all pdu messages from one sender are combined to one long string
                Map<String,String> messages = new HashMap<String,String>();

                Object[] pdus = (Object[]) bundle.get("pdus");

                for (Object pdu: pdus) {
                    SmsMessage msg = SmsMessage.createFromPdu((byte[])pdu);
                    String sender = msg.getOriginatingAddress();
                    String text = msg.getMessageBody();

                    if (messages.containsKey(sender)) {
                        String newText = messages.get(sender) + text;
                        messages.put(sender,newText);
                    } else {
                        messages.put(sender,text);
                    }

                }
                // every message in a dict is checked against filters
                // and is forwarded if it matches
                for (String sender: messages.keySet()) {

                    String message = messages.get(sender);

                    // also seems to work with single-part messages
                    String toSend = "From"+sender + ": " + message;
                    ArrayList<String> dividedMessage = SmsManager.getDefault().divideMessage(toSend);

                    SmsManager.getDefault()
                            .sendMultipartTextMessage(number,null,dividedMessage,null);
                }
            }
        }
    }
}