Android后台来电检测：利用前台服务实现持久化监听

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.calldetector">

    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

    <application
        ...
        <service
            android:name=".CallDetectionService"
            android:enabled="true"
            android:exported="false" />

        <receiver
            android:name=".BootReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </receiver>
    </application>
</manifest>

// BootReceiver.java
package com.example.calldetector;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.util.Log;

public class BootReceiver extends BroadcastReceiver {
    private static final String TAG = "BootReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        if (Intent.ACTION_BOOT_COMPLETED.equals(intent.getAction())) {
            Log.d(TAG, "Boot completed, starting CallDetectionService.");
            Intent serviceIntent = new Intent(context, CallDetectionService.class);
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                // For Android O and above, use startForegroundService
                context.startForegroundService(serviceIntent);
            } else {
                context.startService(serviceIntent);
            }
        }
    }
}

// CallDetectionService.java
package com.example.calldetector;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.os.Build;
import android.os.IBinder;
import android.telephony.PhoneStateListener;
import android.telephony.TelephonyManager;
import android.util.Log;

import androidx.annotation.Nullable;
import androidx.core.app.NotificationCompat;

public class CallDetectionService extends Service {

    private static final String TAG = "CallDetectionService";
    private static final String CHANNEL_ID = "CallDetectionChannel";
    private static final int NOTIFICATION_ID = 101;

    private TelephonyManager telephonyManager;
    private PhoneStateListener phoneStateListener;

    @Override
    public void onCreate() {
        super.onCreate();
        Log.d(TAG, "Service onCreate");
        // 初始化电话管理器和监听器
        telephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
        phoneStateListener = new PhoneStateListener() {
            @Override
            public void onCallStateChanged(int state, String phoneNumber) {
                super.onCallStateChanged(state, phoneNumber);
                switch (state) {
                    case TelephonyManager.CALL_STATE_IDLE:
                        Log.d(TAG, "Call State: IDLE - No call activity.");
                        // 电话挂断或空闲
                        break;
                    case TelephonyManager.CALL_STATE_RINGING:
                        Log.d(TAG, "Call State: RINGING - Incoming call from: " + phoneNumber);
                        // 来电响铃
                        // 在这里处理来电逻辑，例如显示来电信息、播放提示音等
                        break;
                    case TelephonyManager.CALL_STATE_OFFHOOK:
                        Log.d(TAG, "Call State: OFFHOOK - Call answered or dialing.");
                        // 电话接通或拨出
                        break;
                }
            }
        };
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d(TAG, "Service onStartCommand");

        // 创建并显示前台通知
        createNotificationChannel();
        Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setContentTitle("来电检测服务")
                .setContentText("正在后台运行，检测来电状态...")
                .setSmallIcon(android.R.drawable.ic_menu_call) // 使用系统图标作为示例
                .setPriority(NotificationCompat.PRIORITY_LOW)
                .build();

        startForeground(NOTIFICATION_ID, notification);

        // 注册电话状态监听器
        if (telephonyManager != null) {
            telephonyManager.listen(phoneStateListener, PhoneStateListener.LISTEN_CALL_STATE);
        }

        // 返回 START_STICKY 表示如果服务被系统杀死，系统会尝试重新创建它
        return START_STICKY;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "Service onDestroy");
        // 在服务销毁时，取消注册电话状态监听器，防止内存泄漏
        if (telephonyManager != null) {
            telephonyManager.listen(phoneStateListener, PhoneStateListener.LISTEN_NONE);
        }
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        // 对于不与Activity绑定的服务，返回null
        return null;
    }

    private void createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel serviceChannel = new NotificationChannel(
                    CHANNEL_ID,
                    "来电检测通知",
                    NotificationManager.IMPORTANCE_LOW
            );
            serviceChannel.setDescription("用于显示来电检测服务正在后台运行的通知。");
            serviceChannel.enableLights(true);
            serviceChannel.setLightColor(Color.BLUE);
            NotificationManager manager = getSystemService(NotificationManager.class);
            if (manager != null) {
                manager.createNotificationChannel(serviceChannel);
            }
        }
    }
}