执行的后台和前台服务

Question

我遇到了一个问题，我需要在后台计算一些并发计算，并在每次执行完成时通知用户。

我看了很多文章。我在其中找到了 Service Class、Intent Service 等。但我发现 24 android os 版本以上崩溃。

Nowadays which method is best to execute the background service in android and why?

Answer 1

以上问题可以使用工作管理器。为了更好地理解，请查看以下内容 link

https://developer.android.com/topic/libraries/architecture/workmanager

Answer 2

执行后台服务的最佳方法是使用系统 AlarmManager class 并在每 XXX 秒后调用警报，但它会耗尽电池电量，但解决方案肯定适合您。要遵循的步骤，

创建警报

    public static void setUpalarm(Context context) {
        Intent intent = new Intent(context, RestartServiceFromTimer.class);
        final PendingIntent pIntent = PendingIntent.getBroadcast(context , 0,
                intent,0);
        // Setup periodic alarm every every half hour from this point onwards
        long firstMillis = System.currentTimeMillis(); // alarm is set right away
        AlarmManager alarm = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
        // First parameter is the type: ELAPSED_REALTIME, ELAPSED_REALTIME_WAKEUP, RTC_WAKEUP
        // Interval can be INTERVAL_FIFTEEN_MINUTES, INTERVAL_HALF_HOUR, INTERVAL_HOUR, INTERVAL_DAY
        long delay = 5 * 1000 * 60; // time sets to 5 minute change accordingly
        long time = System.currentTimeMillis() + delay;

        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT)
            alarm.set(AlarmManager.RTC_WAKEUP, time, pIntent);
        else if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.KITKAT && Build.VERSION.SDK_INT < Build.VERSION_CODES.M)
            alarm.setExact(AlarmManager.RTC_WAKEUP, time, pIntent);
        else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            alarm.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, time, pIntent);
        }

2 创建广播接收器并重新启动服务并再次安排警报

    public class RestartServiceFromTimer extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        Log.d("Task Trigger","Task is triggered");
        if(!isMyServiceRunning(DetectIncomonCallService.class,context.getApplicationContext()))
        { Intent myserviceIntent = new Intent(context.getApplicationContext(),Service.class);
            //start your background service here
            if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.O)
            {
                ContextCompat.startForegroundService(context.getApplicationContext(),myserviceIntent);//this is for forground service


            }
            else
            {
                context.startService(myserviceIntent);
            }
        }
        MainActivity.setUpalarm(context.getApplicationContext());
    }
    private boolean isMyServiceRunning(Class<?> serviceClass,Context context) {
        ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        for (ActivityManager.RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
            if (serviceClass.getName().equals(service.service.getClassName())) {
                return true;
            }
        }
        return false;
    }
}

3 像这样从 main activity 调用方法

setUpalarm(MainActivity.this)

Answer 3

You can use Foreground Service for android OREO and higher versions and for below OREO Android version, you can use background STICKY, NON_STICKEY services. From the service, you can broadcast your action with value when your calculation is completed.

执行的后台和前台服务

Background and foreground Service For Execution

java

service

android

background

foreground