android - 继续运行后台服务(Android)

Question

我在用户登录后启动了后台服务，即使在 Activity 被“扔到垃圾箱”之后也应该可以工作。服务显示它正在运行的通知，注册两个广播接收器以监视 wifi 和手机状态，并且应该继续运行直到 token 未过期或用户注销。
一切正常，但服务被android杀死。唯一的解决方案真正有效是这篇文章的说明
http://nine-faq.9folders.com/articles/37422-stop-your-huawei-smartphone-from-closing-apps-when-you-lock-the-screen
不幸的是，这种解决方案是 Not Acceptable ，因为它依赖于用户。
由 C# 使用 Xamarin 创建的代码，但如果有人知道如何以编程方式从文章中实现解决方案，即使在其他语言(java，kotlin)中，我也会很高兴提供有用的建议
显现

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
          android:versionCode="1" 
          android:versionName="1.0" 
          package="com.companyname.com.bgapptest">
  <uses-sdk android:minSdkVersion="25" android:targetSdkVersion="28" />
  <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme">
    <service
       android:name="com.BGAppTest.BackgroundService"
       android:enabled="true"
       android:exported="false"/>
  </application>
  <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
  <uses-permission android:name="android.permission.CALL_PHONE" />
  <uses-permission android:name="android.permission.INTERNET" />
  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
  <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
  <uses-permission android:name="android.permission.READ_PHONE_STATE" />
  <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
  <uses-permission android:name="android.permission.WAKE_LOCK" />
  <uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS" />
</manifest>

从 Activity 开始服务
Activity

    using System;
using System.Linq;
using Android.App;
using Android.Content;
using Android.Content.PM;
using Android.OS;
using Android.Provider;
using Android.Runtime;
using Android.Support.Design.Widget;
using Android.Support.V7.App;
using Android.Views;
using Android.Widget;
using AlertDialog = Android.Support.V7.App.AlertDialog;

namespace com.BGAppTest
{
    [Activity(Label = "@string/app_name", Theme = "@style/AppTheme.NoActionBar", MainLauncher = true)]
    public class MainActivity : AppCompatActivity
    {
        public static string HOPE = "Nothing";
        string[] perms = new string[] { "android.permission.ACCESS_FINE_LOCATION", "android.permission.ACCESS_COARSE_LOCATION", "android.permission.ACCESS_NETWORK_STATE", "android.permission.READ_PHONE_STATE","android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS"};

        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            SetContentView(Resource.Layout.activity_main);
            Android.Support.V7.Widget.Toolbar toolbar = FindViewById<Android.Support.V7.Widget.Toolbar>(Resource.Id.toolbar);
            SetSupportActionBar(toolbar);
            FloatingActionButton fab = FindViewById<FloatingActionButton>(Resource.Id.fab);
            fab.Click += FabOnClick;
            HOPE = DateTime.Now.ToString();
            StartService();
        }

        public override bool OnCreateOptionsMenu(IMenu menu)
        {
            MenuInflater.Inflate(Resource.Menu.menu_main, menu);
            return true;
        }

        public override bool OnOptionsItemSelected(IMenuItem item)
        {
            int id = item.ItemId;
            if (id == Resource.Id.action_settings)
            {
                return true;
            }

            return base.OnOptionsItemSelected(item);
        }

        private void FabOnClick(object sender, EventArgs eventArgs)
        {
            View view = (View)sender;
            Intent service = new Intent(this, typeof(BackgroundService));
            StopService(service);
        }

        protected void IGnoreBatteryActivity()
        {
            PowerManager m = GetSystemService(PowerService) as PowerManager;
            Intent intent = new Intent();
            if (m.IsIgnoringBatteryOptimizations(this.PackageName))
            {
                //intent.SetAction(Settings.ActionIgnoreBatteryOptimizationSettings);
            }
            else
            {
                intent.SetAction(Settings.ActionRequestIgnoreBatteryOptimizations);
                intent.SetData(Android.Net.Uri.Parse("package:" + PackageName));
                StartActivity(intent);

            }

        }

        void StartService()
        {
            foreach (var p in perms)
            {
                if (CheckSelfPermission(p) == Permission.Denied)
                {
                    RequestPermissions(perms, 2);
                    return;
                }
            }
            IGnoreBatteryActivity();
            Intent service = new Intent(this, typeof(BackgroundService));
            if (Build.VERSION.SdkInt >= BuildVersionCodes.O)
                StartForegroundService(service);
            else
                StartService(service);

        }

        public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Permission[] grantResults)
        {
            base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
            if (grantResults.Any(x => x == Permission.Denied))
            {
                RunOnUiThread(() =>
                {
                    new AlertDialog.Builder(this)
                       .SetMessage("Uprawnienia są wymagane.Chcesz nadać uprawnienia?")
                       .SetNegativeButton("Nie", delegate
                       {
                           this.FinishAffinity();
                       })
                       .SetPositiveButton("Tak", delegate
                       {
                           RequestPermissions(perms, requestCode);
                       })
                       .SetCancelable(false)
                       .Create()
                       .Show();
                });
            }
            else
                StartService();
        }

    }
}

服务

    [Service(Name = "com.BGAppTest.BackgroundService")]
public class BackgroundService : Service
{
    NetworkChangeReceiver networkReceiver;
    PhoneCallsReceiver receiver;
    const int Service_Running_Notification_ID = 937;
    public bool isStarted = false;
    PowerManager.WakeLock wakeLock;
    public BackgroundService()
    {

    }
    [return: GeneratedEnum]
    public override StartCommandResult OnStartCommand(Intent intent, [GeneratedEnum] StartCommandFlags flags, int startId)
    {
        if (isStarted)
            return StartCommandResult.Sticky;
        isStarted = true;
        PowerManager m = GetSystemService(Context.PowerService) as PowerManager;
        wakeLock = m.NewWakeLock(WakeLockFlags.Partial, "MYWeakLock");
        wakeLock.Acquire();
        return StartCommandResult.Sticky;
    }
    public override void OnCreate()
    {
        base.OnCreate();
        RegisterForegroundService();
        RegisterWifiReceiver();
        RegisterPhoneReceiver();

    }



    public void RegisterForegroundService()
    {
        Notification notification = BuildNotification("Title","Text");
        StartForeground(Service_Running_Notification_ID, notification);
    }


    Notification BuildNotification(string title, string message)
    {
        NotificationCompat.Builder notificationBuilder = null;
        if (Build.VERSION.SdkInt >= BuildVersionCodes.O)
        {
            String NOTIFICATION_CHANNEL_ID = "com.BGAppTest";
            NotificationChannel chan = new NotificationChannel(NOTIFICATION_CHANNEL_ID, "MY_Foreground", NotificationImportance.High);
            NotificationManager manager = (NotificationManager)GetSystemService(Context.NotificationService);
            manager.CreateNotificationChannel(chan);
            notificationBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID);
        }
        else
            notificationBuilder = new NotificationCompat.Builder(this);

        return notificationBuilder
          .SetSmallIcon(Resource.Drawable.ic_mtrl_chip_checked_black)
           .SetContentTitle(Resources.GetString(Resource.String.app_name))
           .SetContentIntent(BuildIntentToShowMainActivity())
           .SetContentTitle(title)
           .SetStyle(new NotificationCompat.BigTextStyle().BigText(message))
           .SetOngoing(true)
           .Build();

    }

    private PendingIntent BuildIntentToShowMainActivity()
    {
        var intent = this.PackageManager.GetLaunchIntentForPackage(this.PackageName);
        intent.AddFlags(ActivityFlags.ClearTop);
        var pendingIntent = PendingIntent.GetActivity(this, 0, intent, PendingIntentFlags.UpdateCurrent);
        return pendingIntent;

    }


    public void RegisterWifiReceiver()
    {
        var networkReceiver = new NetworkChangeReceiver();
        IntentFilter intentFilters = new IntentFilter();
        intentFilters.AddAction("android.net.conn.CONNECTIVITY_CHANGE");
        RegisterReceiver(networkReceiver, intentFilters);
    }
    public void RegisterPhoneReceiver()
    {
        var receiver = new PhoneCallsReceiver();
        IntentFilter intentFilters = new IntentFilter();
        intentFilters.AddAction("android.intent.action.PHONE_STATE");
        RegisterReceiver(receiver, intentFilters);

    }

    public override IBinder OnBind(Intent intent)
    {
        return null;
    }
    #region Session checker
    //TODO:przenieść tą fukcionalność do odzielnego serwisu
    System.Timers.Timer timers = new System.Timers.Timer();
    private void StartTokenExpiredTimer()
    {
    }

    #endregion
    public override void OnDestroy()
    {
        base.OnDestroy();
        try
        {
            UnregisterReceiver(receiver);
            UnregisterReceiver(networkReceiver);
        }
        catch { }

    }
}

接收器

using Android.Content;
using Android.Widget;


namespace com.BGAppTestReceivers
{
    public class NetworkChangeReceiver: BroadcastReceiver
    {

        static NetworkChangeReceiver()
        {

        }
        public NetworkChangeReceiver()
        {
        }
        public override async void OnReceive(Context context, Intent intent)
        {
            Toast.MakeText(context, "BGNetworkChange", ToastLength.Short).Show();

        }


    }

    public class PhoneCallsReceiver : BroadcastReceiver
    {

        static PhoneCallsReceiver()
        {

        }
        public PhoneCallsReceiver()
        {
        }
        public override async void OnReceive(Context context, Intent intent)
        {
            Toast.MakeText(context, "BGPhoneChange", ToastLength.Short).Show();
        }

    }


}

2020 年 9 月 26 日更新
我添加了我的示例应用程序的完整代码，让它尽可能简单
2020 年 9 月 30 日更新
添加 android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS和 ActionRequestIgnoreBatteryOptimizations

Answer 1

您必须请求许可才能使您的应用免于省电和应用待机模式。
您可以先从 手动尝试设置 > 应用程序 > 特殊应用程序访问 > 电池优化 > 为您的应用程序关闭优化 .
如果它适合您，那么您可以要求用户使用以下权限将您的应用列入白名单

android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS