Android应用从最近任务移除后无法接收短信并处理的问题求助

你的核心问题是应用从最近任务列表移除后，无法接收并处理短信，原因主要有两点：

1. 静态注册的BroadcastReceiver在Android 8+后台限制下，应用进程被杀死后无法被系统唤醒触发广播；
2. 你通过静态mListener绑定MainActivity实例，当Activity销毁后mListener变为null，即使广播触发也会空指针，无法处理短信。

下面是可行的解决方案，基于前台服务+动态注册广播接收器实现，能保证应用在后台甚至最近任务被移除时仍能处理短信。

步骤1：创建前台服务处理短信逻辑 #

前台服务可以保持应用进程活跃，不受后台杀死限制，同时在服务内部动态注册短信广播，直接处理短信计算与存储。

package com.example.myapplication;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.IBinder;
import android.telephony.SmsMessage;
import androidx.core.app.NotificationCompat;

public class SmsProcessingService extends Service {
    private static final String CHANNEL_ID = "SmsServiceChannel";
    private BroadcastReceiver smsReceiver;

    @Override
    public void onCreate() {
        super.onCreate();
        // 创建通知渠道（Android 8+必填）
        createNotificationChannel();
        // 启动前台服务，显示常驻通知
        startForeground(1, buildNotification());

        // 动态注册短信广播接收器
        smsReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                if ("android.provider.Telephony.SMS_RECEIVED".equals(intent.getAction())) {
                    Object[] pdus = (Object[]) intent.getExtras().get("pdus");
                    for (Object pdu : pdus) {
                        SmsMessage smsMessage = SmsMessage.createFromPdu((byte[]) pdu);
                        String message = smsMessage.getMessageBody();
                        // 执行你的计算逻辑并保存到SharedPreferences
                        processAndSaveMessage(message);
                    }
                }
            }
        };

        IntentFilter filter = new IntentFilter("android.provider.Telephony.SMS_RECEIVED");
        filter.setPriority(999);
        registerReceiver(smsReceiver, filter);
    }

    // 替换成你的实际计算逻辑
    private void processAndSaveMessage(String message) {
        // 示例计算：假设提取数字求和
        int total = 0;
        for (char c : message.toCharArray()) {
            if (Character.isDigit(c)) {
                total += Integer.parseInt(String.valueOf(c));
            }
        }
        // 保存到SharedPreferences
        SharedPreferences sp = getSharedPreferences("spent", MODE_PRIVATE);
        SharedPreferences.Editor editor = sp.edit();
        editor.putString("spent", String.valueOf(total));
        editor.apply();
    }

    private void createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(
                    CHANNEL_ID,
                    "短信处理服务",
                    NotificationManager.IMPORTANCE_LOW
            );
            NotificationManager manager = getSystemService(NotificationManager.class);
            manager.createNotificationChannel(channel);
        }
    }

    private Notification buildNotification() {
        return new NotificationCompat.Builder(this, CHANNEL_ID)
                .setContentTitle("短信处理中")
                .setContentText("应用正在后台处理短信")
                .setSmallIcon(R.mipmap.ic_launcher)
                .build();
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        // 注销广播接收器，避免内存泄漏
        if (smsReceiver != null) {
            unregisterReceiver(smsReceiver);
        }
    }
}

步骤2：修改MainActivity启动前台服务 #

移除原来的Listener绑定逻辑，改为启动前台服务，并申请必要的权限。

package com.example.myapplication;

import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
import android.Manifest;

public class MainActivity extends AppCompatActivity {
    private TextView textView3;
    private TextView textView4;
    private static final int PERMISSION_REQUEST_CODE = 100;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView3 = findViewById(R.id.textView10);
        textView4 = findViewById(R.id.textView7);

        // 读取SharedPreferences显示数据
        SharedPreferences ts = getSharedPreferences("spent", MODE_PRIVATE);
        textView3.setText(ts.getString("spent", "0"));

        // 申请必要权限
        requestRequiredPermissions();

        // 启动前台服务
        Intent serviceIntent = new Intent(this, SmsProcessingService.class);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            startForegroundService(serviceIntent);
        } else {
            startService(serviceIntent);
        }

        textView4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                SharedPreferences sp = getSharedPreferences("login-auth", MODE_PRIVATE);
                SharedPreferences.Editor spe = sp.edit();
                spe.putBoolean("login-auth", false).apply();
                Intent intent = new Intent(MainActivity.this, login.class);
                startActivity(intent);
            }
        });
    }

    private void requestRequiredPermissions() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            String[] permissions;
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
                permissions = new String[]{
                        Manifest.permission.RECEIVE_SMS,
                        Manifest.permission.READ_SMS,
                        Manifest.permission.POST_NOTIFICATIONS
                };
            } else {
                permissions = new String[]{
                        Manifest.permission.RECEIVE_SMS,
                        Manifest.permission.READ_SMS
                };
            }

            boolean needRequest = false;
            for (String perm : permissions) {
                if (checkSelfPermission(perm) != PackageManager.PERMISSION_GRANTED) {
                    needRequest = true;
                    break;
                }
            }
            if (needRequest) {
                requestPermissions(permissions, PERMISSION_REQUEST_CODE);
            }
        }
    }
}

步骤3：修改AndroidManifest.xml #

添加前台服务声明，移除原来的静态广播接收器（改用动态注册），补充必要权限。

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" >
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-feature
        android:name="android.hardware.telephony"
        android:required="false" />

    <uses-permission android:name="android.permission.RECEIVE_SMS" />
    <uses-permission android:name="android.permission.READ_SMS" />
    <!-- 前台服务权限 -->
    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
    <!-- Android 13+通知权限 -->
    <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Material3.Light.NoActionBar"
        tools:targetApi="31" >
        <activity
            android:name=".register"
            android:theme="@style/Theme.Material3.Light.NoActionBar"
            android:parentActivityName=".login"
            android:exported="false" />
        <activity
            android:name=".MainActivity"
            android:theme="@style/Theme.Material3.Light.NoActionBar"
            android:exported="false"/>

        <activity
            android:name=".login"
            android:theme="@style/Theme.Material3.Light.NoActionBar"
            android:exported="true" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <!-- 声明前台服务 -->
        <service
            android:name=".SmsProcessingService"
            android:foregroundServiceType="dataSync"
            android:exported="false"/>

        <!-- 移除静态注册的广播接收器，改用服务内动态注册 -->
    </application>

</manifest>

额外注意事项 #

1. 部分国产手机厂商有严格的后台管理机制，需要手动将应用加入后台白名单或自启动列表，否则前台服务可能被强制杀死；
2. 前台服务必须显示常驻通知，这是系统强制要求，不能隐藏；
3. 测试时请使用真实设备，模拟器的短信广播可能存在兼容性问题。

内容的提问来源于stack exchange，提问作者Matrix Gaming