android 前台保活 service

引用：https://blog.csdn.net/qq_34195507/article/details/103634396

1.DeskService 前台服务

package com.cpsc.livedemo;

import android.app.Notification;
import android.app.NotificationManager;
import android.app.Service;
import android.content.Intent;
import android.os.Build;
import android.os.IBinder;
import androidx.annotation.Nullable;  //原文引用高版本已不可用,已修改
import android.util.Log;


public class DeskService extends Service {

    private static final String TAG = "DaemonService";
    public static final int NOTICE_ID = 100;

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

    @Override
    public void onCreate() {
        super.onCreate();
        Log.d(TAG, "DaemonService---->onCreate被调用，启动前台service");
        //如果API大于18，需要弹出一个可见通知
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
            Notification.Builder builder = new Notification.Builder(this);
            builder.setSmallIcon(R.mipmap.ic_launcher);
            builder.setContentTitle("KeepAppAlive");
            builder.setContentText("DaemonService is runing...");
            startForeground(NOTICE_ID, builder.build());
            // 如果觉得常驻通知栏体验不好
            // 可以通过启动CancelNoticeService，将通知移除，oom_adj值不变
            Intent intent = new Intent(this, CancelNoticeService.class);
            startService(intent);
        } else {
            startForeground(NOTICE_ID, new Notification());
        }
    }


    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // 如果Service被终止
        // 当资源允许情况下，重启service
        return START_STICKY;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        // 如果Service被杀死，干掉通知
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
            NotificationManager mManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
            mManager.cancel(NOTICE_ID);
        }
        Log.d(TAG, "DaemonService---->onDestroy，前台service被杀死");
        // 重启自己
        Intent intent = new Intent(getApplicationContext(), DeskService.class);
        startService(intent);
    }

}

2 移除前台Service通知栏标志

package com.cpsc.livedemo;

import android.app.Notification;
import android.app.NotificationManager;
import android.app.Service;
import android.content.Intent;
import android.os.Build;
import android.os.IBinder;
import android.os.SystemClock;
import androidx.annotation.Nullable;


public class CancelNoticeService extends Service {
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN_MR2) {
            Notification.Builder builder = new Notification.Builder(this);
            builder.setSmallIcon(R.mipmap.ic_launcher);
            startForeground(DeskService.NOTICE_ID, builder.build());
            // 开启一条线程，去移除DaemonService弹出的通知
            new Thread(new Runnable() {
                @Override
                public void run() {
                    // 延迟1s
                    SystemClock.sleep(1000);
                    // 取消CancelNoticeService的前台
                    stopForeground(true);
                    // 移除DaemonService弹出的通知
                    NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
                    manager.cancel(DeskService.NOTICE_ID);
                    // 任务完成，终止自己
                    stopSelf();
                }
            }).start();
        }
        return super.onStartCommand(intent, flags, startId);
    }
}

3  注册服务到AndroidManifest.xml

<service
    android:name=".DeskService"
    android:enabled="true"
    android:exported="true"
    android:process=":daemon_service" />


<service
    android:name=".CancelNoticeService"
    android:enabled="true"
    android:exported="true"
    android:process=":service" />

4  启动服务

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_child_light_sensor);
      //启动服务
        startService(new Intent(this, DeskService.class));


    }