AlarmManager守护服务和隐藏桌面图标

1、主要内容

本章记录几段常用代码：
1、如何使用AlarmManager守护服务
2、如何判断某服务是否正在运行
2、如何暂时禁用Android的组件

2、使用AlarmManager守护服务

BootReceiver.java

@Override
public void onReceive(Context context, Intent intent) {
    //接收开机启动广播，启动服务，开启alarm定时任务
    if (intent.getAction().equals(Intent.ACTION_BOOT_COMPLETED)) {
        //xxx.class我们要守护的服务
        Intent serviceIntent = new Intent(context, xxxx.class);
        context.startService(serviceIntent);
        startAlarmEvent(context);
    }
    //监听自定义广播，开启alarm定时任务
    if (intent.getAction().equals("xxxxx")) {
        startAlarmEvent(context);
    }

     //监听自定义广播，关闭alarm定时任务
    if (intent.getAction().equals("cn.zcgames.ghostclaw.action.STOP_SERVICE")) {
        Log.d(Tag, "Receive Stop Service Completed broadcast, start Alarm");
        stopAlarmEvent(context);
    }
}

//开启定时任务，手动开启的时候调用
private void startAlarmEvent(Context context) {
    Intent alarmIntent = new Intent(context, AlarmReceiver.class);
    //listen_receiver为AlarmReceiver.java注册的感兴趣的广播
    alarmIntent.setAction("listen_receiver");
    PendingIntent sender = PendingIntent.getBroadcast(context, 0,
            alarmIntent, 0);
    long firstime = SystemClock.elapsedRealtime();
    AlarmManager alarmManager = (AlarmManager) context
            .getSystemService(Context.ALARM_SERVICE);
    //每6秒钟发送一次广播,API 23后，最短时间间隔为6秒
    alarmManager.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, firstime, 10 * 6000, sender);
}
//关闭定时任务，手动关闭的时候调用，防止自己也停止不了
private void stopAlarmEvent(Context context) {
    Intent alarmIntent = new Intent(context, AlarmReceiver.class);
    //listen_receiver为AlarmReceiver.java注册的感兴趣的广播
    alarmIntent.setAction("listen_receiver");
    PendingIntent sender = PendingIntent.getBroadcast(context, 0,
            alarmIntent, 0);
    AlarmManager alarmManager = (AlarmManager) context
            .getSystemService(Context.ALARM_SERVICE);
    //取消发送广播
    alarmManager.cancel(sender);
}

AlarmReceiver.java

@Override
public void onReceive(Context context, Intent intent) {
    if(intent.getAction().equals("listen_receiver")) {
        //如果监听的服务挂掉了，则启动服务
        if (serviceIsRunnting(context, "xxxService")) {
            Intent serviceIntent = new Intent(context, xxxService.class);
            context.startService(serviceIntent);
        }
    }
}

2、如何判断某服务是否正在运行

//判断服务是否在运行
boolean serviceIsRunnting(Context context,  String servcieName) {
    boolean isRunning = false;
    ActivityManager activityManager=null;
    List<ActivityManager.RunningServiceInfo> serviceList=null;

    try{
        activityManager = (ActivityManager)context.getSystemService(Context.ACTIVITY_SERVICE);
    }catch (Exception e){
        e.printStackTrace();
    }
    if(activityManager != null){
        serviceList = activityManager.getRunningServices(Integer.MAX_VALUE);
    }

    if (!(serviceList.size()>0)) {
        return false;
    }

    for (int i=0; i<serviceList.size(); i++) {
        if (serviceList.get(i).service.getClassName().equals(servcieName)) {
            isRunning = true;
            break;
        }
    }
    return isRunning;
}

3、如何暂时禁用Android的组件

private void setComponentState(boolean enable){
    //xxx为app的某组件，我这里是receiver
    final ComponentName alarmReceiver = new ComponentName(getApplication(), xxxx.class);
    final PackageManager packageManager = getApplication().getPackageManager();

    if(enable){
        packageManager.setComponentEnabledSetting(alarmReceiver, PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
                PackageManager.DONT_KILL_APP);
    }else{
        packageManager.setComponentEnabledSetting(alarmReceiver, PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
                PackageManager.DONT_KILL_APP);
    }
}

根据我的使用经验，当在应用中禁用某组件后，系统会记录此状态，直接在as上点运行，替换原来的应用或者重启手机，系统仍然是禁用的(卸载后再安装系统会删除状态记录).

所以各位使用的时候需要注意到这一点，禁用后记得打开。

PS: 如果禁止的是主MainActivity，则桌面图标会消失