C#-Xamarin在断电后未收到本地通知_C#_Xamarin.forms_Xamarin.android

C#-Xamarin在断电后未收到本地通知

c# xamarin.forms xamarin.android

C#-Xamarin在断电后未收到本地通知,c#,xamarin.forms,xamarin.android,C#,Xamarin.forms,Xamarin.android,我已经为我的Xamarin应用程序实现了一个通知服务，除非我关闭手机，否则该服务将正常工作。是否有方法启动服务以确保即使在设备关闭后也能发送通知接口： public interface INotification { void Remind(long date, string title, string message); } android文件中的实现： using Xamarin.Forms; using Plannr.Droid; using Android.Support.V

我已经为我的Xamarin应用程序实现了一个通知服务，除非我关闭手机，否则该服务将正常工作。是否有方法启动服务以确保即使在设备关闭后也能发送通知

接口：

public interface INotification
{
    void Remind(long date, string title, string message);
}

android文件中的实现：

using Xamarin.Forms;
using Plannr.Droid;
using Android.Support.V4.App;
using Android.Content;
using Android.App;
using Android.OS;

[assembly: Dependency(typeof(Notification_Android))]
namespace Plannr.Droid
{
public class Notification_Android : INotification
{
    void INotification.Remind(long date, string title, string message)
    {

        Intent alarmIntent = new Intent(Forms.Context, typeof(AlarmReceiver));
        alarmIntent.PutExtra("message", message);
        alarmIntent.PutExtra("title", title);

        PendingIntent pendingIntent = PendingIntent.GetBroadcast(Forms.Context, 0, alarmIntent, 0);
        AlarmManager alarmManager = (AlarmManager)Forms.Context.GetSystemService(Context.AlarmService);

        //TODO: For demo set after 5 seconds.
        alarmManager.Set(AlarmType.ElapsedRealtime, SystemClock.ElapsedRealtime() + date, pendingIntent);
    }

    [BroadcastReceiver]
    public class AlarmReceiver : BroadcastReceiver
    {
        public override void OnReceive(Context context, Intent intent)
        {
            var message = intent.GetStringExtra("message");
            var title = intent.GetStringExtra("title");
            var notIntent = context.PackageManager.GetLaunchIntentForPackage(context.PackageName);
            intent.AddFlags(ActivityFlags.ClearTop);
            notIntent.AddFlags(ActivityFlags.ClearTop);
            var contentIntent = PendingIntent.GetActivity(context, 0, notIntent, PendingIntentFlags.UpdateCurrent);
            var manager = NotificationManagerCompat.From(context);
            var style = new NotificationCompat.BigTextStyle();
            style.BigText(message);

            //Generate a notification with just short text and small icon
            var builder = new NotificationCompat.Builder(context)
                .SetSmallIcon(Resource.Drawable.icon)
                            .SetContentIntent(contentIntent)
                            .SetContentTitle(title)
                            .SetContentText(message)
                            .SetStyle(style)
                            .SetWhen(Java.Lang.JavaSystem.CurrentTimeMillis())
                            .SetAutoCancel(true);
            builder.SetVibrate((new long[] { 300, 200, 100, 200}));
            var notification = builder.Build();
            Android.App.Application.Context.StartService(intent);
            manager.Notify(1, notification);
        }
    }
}
}

您必须有这样的服务和广播接收器（这是一个旧代码）：

Android依赖服务：

using System;
using XXX.Droid.LocalNotifications.Dependency;
using XXX.LocalNotifications.Interfaces;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Android.Content;
using Android.App;
using Xamarin.Forms;
using XXX.LocalNotifications;

[assembly: Dependency (typeof (LocalNotificationManager_Android))]
namespace XXX.Droid.LocalNotifications.Dependency
{
    public class LocalNotificationManager_Android: ILocalNotificationManager
    {
        #region ILocalNotificationManager implementation

        public void RegisterLocalNotification (Notification notification)
        {
            RegisterNotification (notification);
        }

        public void RegisterLocalNotification (List<Notification> notifications)
        {
            foreach (var notification in notifications) {
                RegisterNotification (notification);
            }
        }

        public void UnRegisterLocalNotification (Notification notification)
        {
            var localNotification = File.ReadAllLines (LogFilePath).FirstOrDefault (noti => noti == notification.Guid);
            if (!string.IsNullOrWhiteSpace (localNotification)) {
                UnRegisterNotification (notification);
            }
        }

        public void UnRegisterLocalNotification (List<Notification> notifications)
        {
            foreach (var notification in notifications) {
                var localNotification = File.ReadAllLines (LogFilePath).FirstOrDefault (noti => noti == notification.Guid);
                if (!string.IsNullOrWhiteSpace (localNotification)) {
                    UnRegisterNotification (notification);
                }
            }
        }

        public void UnRegisterAllNotifications ()
        {
            try{
                var notificationInfo = File.ReadAllLines(LogFilePath);
                foreach(var line in notificationInfo)
                {
                    try{
                        var notification = new Notification(line);
                        UnRegisterNotification(notification);
                    }catch(Exception ex){
                        Console.WriteLine(ex.Message);
                    }
                }
                File.Delete(LogFilePath);
            }catch(Exception ex){
                Console.WriteLine(ex.Message);
            }
        }

        public void RegisterService ()
        {
            if (!File.Exists (LogFilePath)) {
                var file= File.Create (LogFilePath);
                file.Close();

            }
        }

        public bool IsServiceRegistered {
            get {
                return true;
            }
        }

        #endregion

        private string LogFilePath
        {
            get{
                var documents = Environment.GetFolderPath (Environment.SpecialFolder.MyDocuments);
                var logFile = Path.Combine (documents, "notificationsinfo.txt");
                if (!File.Exists (logFile)) {
                    var file= File.Create (logFile);
                    file.Close();
                }
                return logFile;
            }
        }

        private void UnRegisterNotification(Notification notification)
        {
            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData (Android.Net.Uri.Parse ("custom://" + notification.Guid));
            intent1.SetAction (notification.Guid);
            intent1.PutExtra ("Title", notification.Title);
            intent1.PutExtra ("Message", notification.Message);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            try{
                AndroidAlarmManager.Cancel (pendingIntent);
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Remove(notification.Guid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }catch(Exception ex) {
                Console.WriteLine(ex.Message);
            }

        }

        private void RegisterNotification(Notification notification)
        {
            if (string.IsNullOrWhiteSpace (notification.Title)) {
                throw new NullReferenceException ("Title must be setted");
            }

            if (string.IsNullOrWhiteSpace(notification.Message)) {
                throw new NullReferenceException ("Message must be setted");
            }

            if (!notification.Date.HasValue) {
                throw new NullReferenceException ("DateTime must be setted");
            }

            if (notification.Date < DateTime.Now && notification.Interval == RepeatInterval.None) {
                throw new ArgumentException ("DateTime must be greater than DateTime.Now");
            }

            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData (Android.Net.Uri.Parse ("custom://" + notification.Guid));
            intent1.SetAction (notification.Guid);
            intent1.PutExtra ("Title", notification.Title);
            intent1.PutExtra ("Message", notification.Message);
            var daysInCurrentMonth = DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            switch (notification.Interval)
            {
                case RepeatInterval.Daily:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay, pendingIntent);
                    break;
                case RepeatInterval.Weekly:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay * 7, pendingIntent);
                    break;
                case RepeatInterval.Monthly:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay * daysInCurrentMonth, pendingIntent);
                    break;
                case RepeatInterval.None:
                    AndroidAlarmManager.Set(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value), pendingIntent);
                    break;
            }

            try{
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Add(notification.Guid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }catch(Exception ex){
                Console.WriteLine(ex.Message);
            }
        }

        public static long GetMilisecondsUntilNextCheck(DateTime next)
        {
            DateTime now = DateTime.Now;
            DateTime todayAtTime = now.Date.AddHours(next.Hour).AddMinutes(next.Minute);
            DateTime nextInstance = now <= todayAtTime ? todayAtTime : todayAtTime.AddDays(1);
            TimeSpan span = nextInstance - now;
            using (var cal = Java.Util.Calendar.GetInstance(Java.Util.TimeZone.Default))
            {
                cal.Set (Java.Util.CalendarField.Millisecond, 0);
                cal.Add(Java.Util.CalendarField.Millisecond, (int)span.TotalMilliseconds);
                return cal.TimeInMillis;
            }
        }

        public void UnRegisterLocalNotification(string notificationGuid)
        {
            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData(Android.Net.Uri.Parse("custom://" + notificationGuid));
            intent1.SetAction(notificationGuid);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            try
            {
                AndroidAlarmManager.Cancel(pendingIntent);
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Remove(notificationGuid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }

        AlarmManager AndroidAlarmManager { get; set; }

        public LocalNotificationManager_Android ()
        {
            AndroidAlarmManager = (AlarmManager) Forms.Context.GetSystemService(Context.AlarmService);
        }
    }
}

using System;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Support.V7.App;

namespace XXX.Droid.LocalNotifications
{
    [Service(Enabled = true)]
    public class CalendarAlarmService : Service
    {
        ServiceBinder binder;
        NotificationManager mManager;

        public override IBinder OnBind (Intent intent)
        {
            binder = new ServiceBinder(this);
            return binder;
        }

        public override void OnCreate ()
        {
            base.OnCreate ();
        }

        public override void OnDestroy ()
        {
            base.OnDestroy ();
        }

        #region implemented abstract members of Service

        public override StartCommandResult OnStartCommand (Intent intent, StartCommandFlags flags, int startId)
        {
            var notificationUID = intent == null ? string.Empty : intent.Action;
            var title = intent.GetStringExtra("Title");
            var message = intent.GetStringExtra("Message");

            if (ApplicationContext == null || this == null)
            {
#if DEBUG
                Console.WriteLine("CalendarAlarmService - OnStartCommand - ApplicationContext == null!");
                return StartCommandResult.Sticky;
#endif
            }

            if (!MainActivity.AppIsInForground(this))
            {
                mManager = (NotificationManager)GetSystemService(NotificationService);
                Intent mainActivityIntent = new Intent(this, typeof(MainActivity));
                mainActivityIntent.SetAction(notificationUID);
                mainActivityIntent.PutExtra("Title", title);
                mainActivityIntent.PutExtra("Message", message);
                mainActivityIntent.PutExtra("Notification", notificationUID);
                mainActivityIntent.SetFlags(ActivityFlags.SingleTop);

                Notification notification =
                    new Notification(Resource.Drawable.icon, "Notificacion", Java.Lang.JavaSystem.CurrentTimeMillis());
                notification.Defaults |= NotificationDefaults.Sound;
                mainActivityIntent.AddFlags(ActivityFlags.SingleTop | ActivityFlags.ClearTop);

                PendingIntent pendingNotificationIntent =
                    PendingIntent.GetActivity(this, 0, mainActivityIntent, PendingIntentFlags.UpdateCurrent);

                notification.Flags |= NotificationFlags.AutoCancel;

                NotificationCompat.Builder builder = new NotificationCompat.Builder(
                            this);
                notification = builder.SetContentIntent(pendingNotificationIntent)
                                      .SetSmallIcon(Resource.Drawable.icon).SetWhen(DateTime.Now.Ticks)
                                      .SetAutoCancel(true).SetContentTitle(title)
                                      .SetDefaults((int)NotificationDefaults.Sound)
                                      //.SetVibrate()
                                      .SetContentText(message).Build();

                if (!string.IsNullOrEmpty(title) && !string.IsNullOrEmpty(message))
                {
                    mManager.Notify(0, notification);
                }
            }

            return base.OnStartCommand (intent, flags, startId);

        }

        #endregion

    }

    public class ServiceBinder : Binder
    {
        CalendarAlarmService service;

        public ServiceBinder(CalendarAlarmService service)
        {
            this.service = service;
        }

        public CalendarAlarmService GetCalendarService()
        {
            return service;
        }
    }
}

using Android.App;
using Android.Content;

namespace XXX.Droid.LocalNotifications
{
    [BroadcastReceiver(Enabled = true)]
    [IntentFilter(new[] { "android.intent.action.BOOT_COMPLETED" })]
    public class CalendarReceiver: BroadcastReceiver
    {
        #region implemented abstract members of BroadcastReceiver

        public override void OnReceive (Context context, Intent intent)
        {
            var notificationUID = intent.Action;
            var title = intent.GetStringExtra ("Title");
            var message = intent.GetStringExtra ("Message");

            Intent service1 = new Intent(context, typeof(CalendarAlarmService));
            service1.SetData(Android.Net.Uri.Parse("custom://" + notificationUID));
            service1.SetAction(notificationUID);
            service1.PutExtra("Title", title);
            service1.PutExtra("Message", message);
            context.StartService(service1);

            if (MainActivity.AppIsInForground(context))
            {
                // App is in Foreground
                GlobalMethods.RecibioNotificacionLocal(intent.Action);
            }
            else {
                // App is in Background
                //App.CrearNotificacionSQL(intent.Action);
            }

            App.Instance.ShowNotification(title, message);
            //Toast.MakeText(Forms.Context, message ,ToastLength.Long).Show();

        }



        #endregion

        public CalendarReceiver ()
        {
        }
    }
}

日历接收者：

using System;
using XXX.Droid.LocalNotifications.Dependency;
using XXX.LocalNotifications.Interfaces;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Android.Content;
using Android.App;
using Xamarin.Forms;
using XXX.LocalNotifications;

[assembly: Dependency (typeof (LocalNotificationManager_Android))]
namespace XXX.Droid.LocalNotifications.Dependency
{
    public class LocalNotificationManager_Android: ILocalNotificationManager
    {
        #region ILocalNotificationManager implementation

        public void RegisterLocalNotification (Notification notification)
        {
            RegisterNotification (notification);
        }

        public void RegisterLocalNotification (List<Notification> notifications)
        {
            foreach (var notification in notifications) {
                RegisterNotification (notification);
            }
        }

        public void UnRegisterLocalNotification (Notification notification)
        {
            var localNotification = File.ReadAllLines (LogFilePath).FirstOrDefault (noti => noti == notification.Guid);
            if (!string.IsNullOrWhiteSpace (localNotification)) {
                UnRegisterNotification (notification);
            }
        }

        public void UnRegisterLocalNotification (List<Notification> notifications)
        {
            foreach (var notification in notifications) {
                var localNotification = File.ReadAllLines (LogFilePath).FirstOrDefault (noti => noti == notification.Guid);
                if (!string.IsNullOrWhiteSpace (localNotification)) {
                    UnRegisterNotification (notification);
                }
            }
        }

        public void UnRegisterAllNotifications ()
        {
            try{
                var notificationInfo = File.ReadAllLines(LogFilePath);
                foreach(var line in notificationInfo)
                {
                    try{
                        var notification = new Notification(line);
                        UnRegisterNotification(notification);
                    }catch(Exception ex){
                        Console.WriteLine(ex.Message);
                    }
                }
                File.Delete(LogFilePath);
            }catch(Exception ex){
                Console.WriteLine(ex.Message);
            }
        }

        public void RegisterService ()
        {
            if (!File.Exists (LogFilePath)) {
                var file= File.Create (LogFilePath);
                file.Close();

            }
        }

        public bool IsServiceRegistered {
            get {
                return true;
            }
        }

        #endregion

        private string LogFilePath
        {
            get{
                var documents = Environment.GetFolderPath (Environment.SpecialFolder.MyDocuments);
                var logFile = Path.Combine (documents, "notificationsinfo.txt");
                if (!File.Exists (logFile)) {
                    var file= File.Create (logFile);
                    file.Close();
                }
                return logFile;
            }
        }

        private void UnRegisterNotification(Notification notification)
        {
            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData (Android.Net.Uri.Parse ("custom://" + notification.Guid));
            intent1.SetAction (notification.Guid);
            intent1.PutExtra ("Title", notification.Title);
            intent1.PutExtra ("Message", notification.Message);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            try{
                AndroidAlarmManager.Cancel (pendingIntent);
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Remove(notification.Guid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }catch(Exception ex) {
                Console.WriteLine(ex.Message);
            }

        }

        private void RegisterNotification(Notification notification)
        {
            if (string.IsNullOrWhiteSpace (notification.Title)) {
                throw new NullReferenceException ("Title must be setted");
            }

            if (string.IsNullOrWhiteSpace(notification.Message)) {
                throw new NullReferenceException ("Message must be setted");
            }

            if (!notification.Date.HasValue) {
                throw new NullReferenceException ("DateTime must be setted");
            }

            if (notification.Date < DateTime.Now && notification.Interval == RepeatInterval.None) {
                throw new ArgumentException ("DateTime must be greater than DateTime.Now");
            }

            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData (Android.Net.Uri.Parse ("custom://" + notification.Guid));
            intent1.SetAction (notification.Guid);
            intent1.PutExtra ("Title", notification.Title);
            intent1.PutExtra ("Message", notification.Message);
            var daysInCurrentMonth = DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            switch (notification.Interval)
            {
                case RepeatInterval.Daily:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay, pendingIntent);
                    break;
                case RepeatInterval.Weekly:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay * 7, pendingIntent);
                    break;
                case RepeatInterval.Monthly:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay * daysInCurrentMonth, pendingIntent);
                    break;
                case RepeatInterval.None:
                    AndroidAlarmManager.Set(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value), pendingIntent);
                    break;
            }

            try{
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Add(notification.Guid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }catch(Exception ex){
                Console.WriteLine(ex.Message);
            }
        }

        public static long GetMilisecondsUntilNextCheck(DateTime next)
        {
            DateTime now = DateTime.Now;
            DateTime todayAtTime = now.Date.AddHours(next.Hour).AddMinutes(next.Minute);
            DateTime nextInstance = now <= todayAtTime ? todayAtTime : todayAtTime.AddDays(1);
            TimeSpan span = nextInstance - now;
            using (var cal = Java.Util.Calendar.GetInstance(Java.Util.TimeZone.Default))
            {
                cal.Set (Java.Util.CalendarField.Millisecond, 0);
                cal.Add(Java.Util.CalendarField.Millisecond, (int)span.TotalMilliseconds);
                return cal.TimeInMillis;
            }
        }

        public void UnRegisterLocalNotification(string notificationGuid)
        {
            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData(Android.Net.Uri.Parse("custom://" + notificationGuid));
            intent1.SetAction(notificationGuid);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            try
            {
                AndroidAlarmManager.Cancel(pendingIntent);
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Remove(notificationGuid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }

        AlarmManager AndroidAlarmManager { get; set; }

        public LocalNotificationManager_Android ()
        {
            AndroidAlarmManager = (AlarmManager) Forms.Context.GetSystemService(Context.AlarmService);
        }
    }
}

using System;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Support.V7.App;

namespace XXX.Droid.LocalNotifications
{
    [Service(Enabled = true)]
    public class CalendarAlarmService : Service
    {
        ServiceBinder binder;
        NotificationManager mManager;

        public override IBinder OnBind (Intent intent)
        {
            binder = new ServiceBinder(this);
            return binder;
        }

        public override void OnCreate ()
        {
            base.OnCreate ();
        }

        public override void OnDestroy ()
        {
            base.OnDestroy ();
        }

        #region implemented abstract members of Service

        public override StartCommandResult OnStartCommand (Intent intent, StartCommandFlags flags, int startId)
        {
            var notificationUID = intent == null ? string.Empty : intent.Action;
            var title = intent.GetStringExtra("Title");
            var message = intent.GetStringExtra("Message");

            if (ApplicationContext == null || this == null)
            {
#if DEBUG
                Console.WriteLine("CalendarAlarmService - OnStartCommand - ApplicationContext == null!");
                return StartCommandResult.Sticky;
#endif
            }

            if (!MainActivity.AppIsInForground(this))
            {
                mManager = (NotificationManager)GetSystemService(NotificationService);
                Intent mainActivityIntent = new Intent(this, typeof(MainActivity));
                mainActivityIntent.SetAction(notificationUID);
                mainActivityIntent.PutExtra("Title", title);
                mainActivityIntent.PutExtra("Message", message);
                mainActivityIntent.PutExtra("Notification", notificationUID);
                mainActivityIntent.SetFlags(ActivityFlags.SingleTop);

                Notification notification =
                    new Notification(Resource.Drawable.icon, "Notificacion", Java.Lang.JavaSystem.CurrentTimeMillis());
                notification.Defaults |= NotificationDefaults.Sound;
                mainActivityIntent.AddFlags(ActivityFlags.SingleTop | ActivityFlags.ClearTop);

                PendingIntent pendingNotificationIntent =
                    PendingIntent.GetActivity(this, 0, mainActivityIntent, PendingIntentFlags.UpdateCurrent);

                notification.Flags |= NotificationFlags.AutoCancel;

                NotificationCompat.Builder builder = new NotificationCompat.Builder(
                            this);
                notification = builder.SetContentIntent(pendingNotificationIntent)
                                      .SetSmallIcon(Resource.Drawable.icon).SetWhen(DateTime.Now.Ticks)
                                      .SetAutoCancel(true).SetContentTitle(title)
                                      .SetDefaults((int)NotificationDefaults.Sound)
                                      //.SetVibrate()
                                      .SetContentText(message).Build();

                if (!string.IsNullOrEmpty(title) && !string.IsNullOrEmpty(message))
                {
                    mManager.Notify(0, notification);
                }
            }

            return base.OnStartCommand (intent, flags, startId);

        }

        #endregion

    }

    public class ServiceBinder : Binder
    {
        CalendarAlarmService service;

        public ServiceBinder(CalendarAlarmService service)
        {
            this.service = service;
        }

        public CalendarAlarmService GetCalendarService()
        {
            return service;
        }
    }
}

using Android.App;
using Android.Content;

namespace XXX.Droid.LocalNotifications
{
    [BroadcastReceiver(Enabled = true)]
    [IntentFilter(new[] { "android.intent.action.BOOT_COMPLETED" })]
    public class CalendarReceiver: BroadcastReceiver
    {
        #region implemented abstract members of BroadcastReceiver

        public override void OnReceive (Context context, Intent intent)
        {
            var notificationUID = intent.Action;
            var title = intent.GetStringExtra ("Title");
            var message = intent.GetStringExtra ("Message");

            Intent service1 = new Intent(context, typeof(CalendarAlarmService));
            service1.SetData(Android.Net.Uri.Parse("custom://" + notificationUID));
            service1.SetAction(notificationUID);
            service1.PutExtra("Title", title);
            service1.PutExtra("Message", message);
            context.StartService(service1);

            if (MainActivity.AppIsInForground(context))
            {
                // App is in Foreground
                GlobalMethods.RecibioNotificacionLocal(intent.Action);
            }
            else {
                // App is in Background
                //App.CrearNotificacionSQL(intent.Action);
            }

            App.Instance.ShowNotification(title, message);
            //Toast.MakeText(Forms.Context, message ,ToastLength.Long).Show();

        }



        #endregion

        public CalendarReceiver ()
        {
        }
    }
}

同样在我编码之后，我意识到有一个NuGet可能更适合使用：

您必须有这样的服务和广播接收器（这是一个旧代码）：

Android依赖服务：

using System;
using XXX.Droid.LocalNotifications.Dependency;
using XXX.LocalNotifications.Interfaces;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Android.Content;
using Android.App;
using Xamarin.Forms;
using XXX.LocalNotifications;

[assembly: Dependency (typeof (LocalNotificationManager_Android))]
namespace XXX.Droid.LocalNotifications.Dependency
{
    public class LocalNotificationManager_Android: ILocalNotificationManager
    {
        #region ILocalNotificationManager implementation

        public void RegisterLocalNotification (Notification notification)
        {
            RegisterNotification (notification);
        }

        public void RegisterLocalNotification (List<Notification> notifications)
        {
            foreach (var notification in notifications) {
                RegisterNotification (notification);
            }
        }

        public void UnRegisterLocalNotification (Notification notification)
        {
            var localNotification = File.ReadAllLines (LogFilePath).FirstOrDefault (noti => noti == notification.Guid);
            if (!string.IsNullOrWhiteSpace (localNotification)) {
                UnRegisterNotification (notification);
            }
        }

        public void UnRegisterLocalNotification (List<Notification> notifications)
        {
            foreach (var notification in notifications) {
                var localNotification = File.ReadAllLines (LogFilePath).FirstOrDefault (noti => noti == notification.Guid);
                if (!string.IsNullOrWhiteSpace (localNotification)) {
                    UnRegisterNotification (notification);
                }
            }
        }

        public void UnRegisterAllNotifications ()
        {
            try{
                var notificationInfo = File.ReadAllLines(LogFilePath);
                foreach(var line in notificationInfo)
                {
                    try{
                        var notification = new Notification(line);
                        UnRegisterNotification(notification);
                    }catch(Exception ex){
                        Console.WriteLine(ex.Message);
                    }
                }
                File.Delete(LogFilePath);
            }catch(Exception ex){
                Console.WriteLine(ex.Message);
            }
        }

        public void RegisterService ()
        {
            if (!File.Exists (LogFilePath)) {
                var file= File.Create (LogFilePath);
                file.Close();

            }
        }

        public bool IsServiceRegistered {
            get {
                return true;
            }
        }

        #endregion

        private string LogFilePath
        {
            get{
                var documents = Environment.GetFolderPath (Environment.SpecialFolder.MyDocuments);
                var logFile = Path.Combine (documents, "notificationsinfo.txt");
                if (!File.Exists (logFile)) {
                    var file= File.Create (logFile);
                    file.Close();
                }
                return logFile;
            }
        }

        private void UnRegisterNotification(Notification notification)
        {
            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData (Android.Net.Uri.Parse ("custom://" + notification.Guid));
            intent1.SetAction (notification.Guid);
            intent1.PutExtra ("Title", notification.Title);
            intent1.PutExtra ("Message", notification.Message);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            try{
                AndroidAlarmManager.Cancel (pendingIntent);
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Remove(notification.Guid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }catch(Exception ex) {
                Console.WriteLine(ex.Message);
            }

        }

        private void RegisterNotification(Notification notification)
        {
            if (string.IsNullOrWhiteSpace (notification.Title)) {
                throw new NullReferenceException ("Title must be setted");
            }

            if (string.IsNullOrWhiteSpace(notification.Message)) {
                throw new NullReferenceException ("Message must be setted");
            }

            if (!notification.Date.HasValue) {
                throw new NullReferenceException ("DateTime must be setted");
            }

            if (notification.Date < DateTime.Now && notification.Interval == RepeatInterval.None) {
                throw new ArgumentException ("DateTime must be greater than DateTime.Now");
            }

            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData (Android.Net.Uri.Parse ("custom://" + notification.Guid));
            intent1.SetAction (notification.Guid);
            intent1.PutExtra ("Title", notification.Title);
            intent1.PutExtra ("Message", notification.Message);
            var daysInCurrentMonth = DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            switch (notification.Interval)
            {
                case RepeatInterval.Daily:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay, pendingIntent);
                    break;
                case RepeatInterval.Weekly:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay * 7, pendingIntent);
                    break;
                case RepeatInterval.Monthly:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay * daysInCurrentMonth, pendingIntent);
                    break;
                case RepeatInterval.None:
                    AndroidAlarmManager.Set(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value), pendingIntent);
                    break;
            }

            try{
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Add(notification.Guid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }catch(Exception ex){
                Console.WriteLine(ex.Message);
            }
        }

        public static long GetMilisecondsUntilNextCheck(DateTime next)
        {
            DateTime now = DateTime.Now;
            DateTime todayAtTime = now.Date.AddHours(next.Hour).AddMinutes(next.Minute);
            DateTime nextInstance = now <= todayAtTime ? todayAtTime : todayAtTime.AddDays(1);
            TimeSpan span = nextInstance - now;
            using (var cal = Java.Util.Calendar.GetInstance(Java.Util.TimeZone.Default))
            {
                cal.Set (Java.Util.CalendarField.Millisecond, 0);
                cal.Add(Java.Util.CalendarField.Millisecond, (int)span.TotalMilliseconds);
                return cal.TimeInMillis;
            }
        }

        public void UnRegisterLocalNotification(string notificationGuid)
        {
            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData(Android.Net.Uri.Parse("custom://" + notificationGuid));
            intent1.SetAction(notificationGuid);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            try
            {
                AndroidAlarmManager.Cancel(pendingIntent);
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Remove(notificationGuid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }

        AlarmManager AndroidAlarmManager { get; set; }

        public LocalNotificationManager_Android ()
        {
            AndroidAlarmManager = (AlarmManager) Forms.Context.GetSystemService(Context.AlarmService);
        }
    }
}

using System;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Support.V7.App;

namespace XXX.Droid.LocalNotifications
{
    [Service(Enabled = true)]
    public class CalendarAlarmService : Service
    {
        ServiceBinder binder;
        NotificationManager mManager;

        public override IBinder OnBind (Intent intent)
        {
            binder = new ServiceBinder(this);
            return binder;
        }

        public override void OnCreate ()
        {
            base.OnCreate ();
        }

        public override void OnDestroy ()
        {
            base.OnDestroy ();
        }

        #region implemented abstract members of Service

        public override StartCommandResult OnStartCommand (Intent intent, StartCommandFlags flags, int startId)
        {
            var notificationUID = intent == null ? string.Empty : intent.Action;
            var title = intent.GetStringExtra("Title");
            var message = intent.GetStringExtra("Message");

            if (ApplicationContext == null || this == null)
            {
#if DEBUG
                Console.WriteLine("CalendarAlarmService - OnStartCommand - ApplicationContext == null!");
                return StartCommandResult.Sticky;
#endif
            }

            if (!MainActivity.AppIsInForground(this))
            {
                mManager = (NotificationManager)GetSystemService(NotificationService);
                Intent mainActivityIntent = new Intent(this, typeof(MainActivity));
                mainActivityIntent.SetAction(notificationUID);
                mainActivityIntent.PutExtra("Title", title);
                mainActivityIntent.PutExtra("Message", message);
                mainActivityIntent.PutExtra("Notification", notificationUID);
                mainActivityIntent.SetFlags(ActivityFlags.SingleTop);

                Notification notification =
                    new Notification(Resource.Drawable.icon, "Notificacion", Java.Lang.JavaSystem.CurrentTimeMillis());
                notification.Defaults |= NotificationDefaults.Sound;
                mainActivityIntent.AddFlags(ActivityFlags.SingleTop | ActivityFlags.ClearTop);

                PendingIntent pendingNotificationIntent =
                    PendingIntent.GetActivity(this, 0, mainActivityIntent, PendingIntentFlags.UpdateCurrent);

                notification.Flags |= NotificationFlags.AutoCancel;

                NotificationCompat.Builder builder = new NotificationCompat.Builder(
                            this);
                notification = builder.SetContentIntent(pendingNotificationIntent)
                                      .SetSmallIcon(Resource.Drawable.icon).SetWhen(DateTime.Now.Ticks)
                                      .SetAutoCancel(true).SetContentTitle(title)
                                      .SetDefaults((int)NotificationDefaults.Sound)
                                      //.SetVibrate()
                                      .SetContentText(message).Build();

                if (!string.IsNullOrEmpty(title) && !string.IsNullOrEmpty(message))
                {
                    mManager.Notify(0, notification);
                }
            }

            return base.OnStartCommand (intent, flags, startId);

        }

        #endregion

    }

    public class ServiceBinder : Binder
    {
        CalendarAlarmService service;

        public ServiceBinder(CalendarAlarmService service)
        {
            this.service = service;
        }

        public CalendarAlarmService GetCalendarService()
        {
            return service;
        }
    }
}

using Android.App;
using Android.Content;

namespace XXX.Droid.LocalNotifications
{
    [BroadcastReceiver(Enabled = true)]
    [IntentFilter(new[] { "android.intent.action.BOOT_COMPLETED" })]
    public class CalendarReceiver: BroadcastReceiver
    {
        #region implemented abstract members of BroadcastReceiver

        public override void OnReceive (Context context, Intent intent)
        {
            var notificationUID = intent.Action;
            var title = intent.GetStringExtra ("Title");
            var message = intent.GetStringExtra ("Message");

            Intent service1 = new Intent(context, typeof(CalendarAlarmService));
            service1.SetData(Android.Net.Uri.Parse("custom://" + notificationUID));
            service1.SetAction(notificationUID);
            service1.PutExtra("Title", title);
            service1.PutExtra("Message", message);
            context.StartService(service1);

            if (MainActivity.AppIsInForground(context))
            {
                // App is in Foreground
                GlobalMethods.RecibioNotificacionLocal(intent.Action);
            }
            else {
                // App is in Background
                //App.CrearNotificacionSQL(intent.Action);
            }

            App.Instance.ShowNotification(title, message);
            //Toast.MakeText(Forms.Context, message ,ToastLength.Long).Show();

        }



        #endregion

        public CalendarReceiver ()
        {
        }
    }
}

日历接收者：

using System;
using XXX.Droid.LocalNotifications.Dependency;
using XXX.LocalNotifications.Interfaces;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Android.Content;
using Android.App;
using Xamarin.Forms;
using XXX.LocalNotifications;

[assembly: Dependency (typeof (LocalNotificationManager_Android))]
namespace XXX.Droid.LocalNotifications.Dependency
{
    public class LocalNotificationManager_Android: ILocalNotificationManager
    {
        #region ILocalNotificationManager implementation

        public void RegisterLocalNotification (Notification notification)
        {
            RegisterNotification (notification);
        }

        public void RegisterLocalNotification (List<Notification> notifications)
        {
            foreach (var notification in notifications) {
                RegisterNotification (notification);
            }
        }

        public void UnRegisterLocalNotification (Notification notification)
        {
            var localNotification = File.ReadAllLines (LogFilePath).FirstOrDefault (noti => noti == notification.Guid);
            if (!string.IsNullOrWhiteSpace (localNotification)) {
                UnRegisterNotification (notification);
            }
        }

        public void UnRegisterLocalNotification (List<Notification> notifications)
        {
            foreach (var notification in notifications) {
                var localNotification = File.ReadAllLines (LogFilePath).FirstOrDefault (noti => noti == notification.Guid);
                if (!string.IsNullOrWhiteSpace (localNotification)) {
                    UnRegisterNotification (notification);
                }
            }
        }

        public void UnRegisterAllNotifications ()
        {
            try{
                var notificationInfo = File.ReadAllLines(LogFilePath);
                foreach(var line in notificationInfo)
                {
                    try{
                        var notification = new Notification(line);
                        UnRegisterNotification(notification);
                    }catch(Exception ex){
                        Console.WriteLine(ex.Message);
                    }
                }
                File.Delete(LogFilePath);
            }catch(Exception ex){
                Console.WriteLine(ex.Message);
            }
        }

        public void RegisterService ()
        {
            if (!File.Exists (LogFilePath)) {
                var file= File.Create (LogFilePath);
                file.Close();

            }
        }

        public bool IsServiceRegistered {
            get {
                return true;
            }
        }

        #endregion

        private string LogFilePath
        {
            get{
                var documents = Environment.GetFolderPath (Environment.SpecialFolder.MyDocuments);
                var logFile = Path.Combine (documents, "notificationsinfo.txt");
                if (!File.Exists (logFile)) {
                    var file= File.Create (logFile);
                    file.Close();
                }
                return logFile;
            }
        }

        private void UnRegisterNotification(Notification notification)
        {
            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData (Android.Net.Uri.Parse ("custom://" + notification.Guid));
            intent1.SetAction (notification.Guid);
            intent1.PutExtra ("Title", notification.Title);
            intent1.PutExtra ("Message", notification.Message);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            try{
                AndroidAlarmManager.Cancel (pendingIntent);
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Remove(notification.Guid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }catch(Exception ex) {
                Console.WriteLine(ex.Message);
            }

        }

        private void RegisterNotification(Notification notification)
        {
            if (string.IsNullOrWhiteSpace (notification.Title)) {
                throw new NullReferenceException ("Title must be setted");
            }

            if (string.IsNullOrWhiteSpace(notification.Message)) {
                throw new NullReferenceException ("Message must be setted");
            }

            if (!notification.Date.HasValue) {
                throw new NullReferenceException ("DateTime must be setted");
            }

            if (notification.Date < DateTime.Now && notification.Interval == RepeatInterval.None) {
                throw new ArgumentException ("DateTime must be greater than DateTime.Now");
            }

            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData (Android.Net.Uri.Parse ("custom://" + notification.Guid));
            intent1.SetAction (notification.Guid);
            intent1.PutExtra ("Title", notification.Title);
            intent1.PutExtra ("Message", notification.Message);
            var daysInCurrentMonth = DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            switch (notification.Interval)
            {
                case RepeatInterval.Daily:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay, pendingIntent);
                    break;
                case RepeatInterval.Weekly:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay * 7, pendingIntent);
                    break;
                case RepeatInterval.Monthly:
                    AndroidAlarmManager.SetRepeating(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value),
                    AlarmManager.IntervalDay * daysInCurrentMonth, pendingIntent);
                    break;
                case RepeatInterval.None:
                    AndroidAlarmManager.Set(AlarmType.RtcWakeup, GetMilisecondsUntilNextCheck(notification.Date.Value), pendingIntent);
                    break;
            }

            try{
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Add(notification.Guid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }catch(Exception ex){
                Console.WriteLine(ex.Message);
            }
        }

        public static long GetMilisecondsUntilNextCheck(DateTime next)
        {
            DateTime now = DateTime.Now;
            DateTime todayAtTime = now.Date.AddHours(next.Hour).AddMinutes(next.Minute);
            DateTime nextInstance = now <= todayAtTime ? todayAtTime : todayAtTime.AddDays(1);
            TimeSpan span = nextInstance - now;
            using (var cal = Java.Util.Calendar.GetInstance(Java.Util.TimeZone.Default))
            {
                cal.Set (Java.Util.CalendarField.Millisecond, 0);
                cal.Add(Java.Util.CalendarField.Millisecond, (int)span.TotalMilliseconds);
                return cal.TimeInMillis;
            }
        }

        public void UnRegisterLocalNotification(string notificationGuid)
        {
            Intent intent1 = new Intent(Forms.Context, typeof(CalendarReceiver));
            intent1.SetData(Android.Net.Uri.Parse("custom://" + notificationGuid));
            intent1.SetAction(notificationGuid);

            PendingIntent pendingIntent = PendingIntent.GetBroadcast(
                Forms.Context, 0, intent1,
                PendingIntentFlags.UpdateCurrent);

            try
            {
                AndroidAlarmManager.Cancel(pendingIntent);
                var notificationInfo = new List<string>(File.ReadAllLines(LogFilePath));
                notificationInfo.Remove(notificationGuid);
                File.WriteAllLines(LogFilePath, notificationInfo);
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }

        AlarmManager AndroidAlarmManager { get; set; }

        public LocalNotificationManager_Android ()
        {
            AndroidAlarmManager = (AlarmManager) Forms.Context.GetSystemService(Context.AlarmService);
        }
    }
}

using System;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Support.V7.App;

namespace XXX.Droid.LocalNotifications
{
    [Service(Enabled = true)]
    public class CalendarAlarmService : Service
    {
        ServiceBinder binder;
        NotificationManager mManager;

        public override IBinder OnBind (Intent intent)
        {
            binder = new ServiceBinder(this);
            return binder;
        }

        public override void OnCreate ()
        {
            base.OnCreate ();
        }

        public override void OnDestroy ()
        {
            base.OnDestroy ();
        }

        #region implemented abstract members of Service

        public override StartCommandResult OnStartCommand (Intent intent, StartCommandFlags flags, int startId)
        {
            var notificationUID = intent == null ? string.Empty : intent.Action;
            var title = intent.GetStringExtra("Title");
            var message = intent.GetStringExtra("Message");

            if (ApplicationContext == null || this == null)
            {
#if DEBUG
                Console.WriteLine("CalendarAlarmService - OnStartCommand - ApplicationContext == null!");
                return StartCommandResult.Sticky;
#endif
            }

            if (!MainActivity.AppIsInForground(this))
            {
                mManager = (NotificationManager)GetSystemService(NotificationService);
                Intent mainActivityIntent = new Intent(this, typeof(MainActivity));
                mainActivityIntent.SetAction(notificationUID);
                mainActivityIntent.PutExtra("Title", title);
                mainActivityIntent.PutExtra("Message", message);
                mainActivityIntent.PutExtra("Notification", notificationUID);
                mainActivityIntent.SetFlags(ActivityFlags.SingleTop);

                Notification notification =
                    new Notification(Resource.Drawable.icon, "Notificacion", Java.Lang.JavaSystem.CurrentTimeMillis());
                notification.Defaults |= NotificationDefaults.Sound;
                mainActivityIntent.AddFlags(ActivityFlags.SingleTop | ActivityFlags.ClearTop);

                PendingIntent pendingNotificationIntent =
                    PendingIntent.GetActivity(this, 0, mainActivityIntent, PendingIntentFlags.UpdateCurrent);

                notification.Flags |= NotificationFlags.AutoCancel;

                NotificationCompat.Builder builder = new NotificationCompat.Builder(
                            this);
                notification = builder.SetContentIntent(pendingNotificationIntent)
                                      .SetSmallIcon(Resource.Drawable.icon).SetWhen(DateTime.Now.Ticks)
                                      .SetAutoCancel(true).SetContentTitle(title)
                                      .SetDefaults((int)NotificationDefaults.Sound)
                                      //.SetVibrate()
                                      .SetContentText(message).Build();

                if (!string.IsNullOrEmpty(title) && !string.IsNullOrEmpty(message))
                {
                    mManager.Notify(0, notification);
                }
            }

            return base.OnStartCommand (intent, flags, startId);

        }

        #endregion

    }

    public class ServiceBinder : Binder
    {
        CalendarAlarmService service;

        public ServiceBinder(CalendarAlarmService service)
        {
            this.service = service;
        }

        public CalendarAlarmService GetCalendarService()
        {
            return service;
        }
    }
}

using Android.App;
using Android.Content;

namespace XXX.Droid.LocalNotifications
{
    [BroadcastReceiver(Enabled = true)]
    [IntentFilter(new[] { "android.intent.action.BOOT_COMPLETED" })]
    public class CalendarReceiver: BroadcastReceiver
    {
        #region implemented abstract members of BroadcastReceiver

        public override void OnReceive (Context context, Intent intent)
        {
            var notificationUID = intent.Action;
            var title = intent.GetStringExtra ("Title");
            var message = intent.GetStringExtra ("Message");

            Intent service1 = new Intent(context, typeof(CalendarAlarmService));
            service1.SetData(Android.Net.Uri.Parse("custom://" + notificationUID));
            service1.SetAction(notificationUID);
            service1.PutExtra("Title", title);
            service1.PutExtra("Message", message);
            context.StartService(service1);

            if (MainActivity.AppIsInForground(context))
            {
                // App is in Foreground
                GlobalMethods.RecibioNotificacionLocal(intent.Action);
            }
            else {
                // App is in Background
                //App.CrearNotificacionSQL(intent.Action);
            }

            App.Instance.ShowNotification(title, message);
            //Toast.MakeText(Forms.Context, message ,ToastLength.Long).Show();

        }



        #endregion

        public CalendarReceiver ()
        {
        }
    }
}

同样在我编码之后，我意识到有一个NuGet可能更适合使用：

我很确定这两个插件都存在相同的问题，即设备断电后通知消失。然后使用我发布的代码，即使设备重新启动，也能正常工作。我知道，这更多的是对原始海报的评论，即插件无法解决他的问题。我很确定这两个插件都存在与他相同的问题，即在设备断电后通知消失。然后使用我发布的代码，即使设备重新启动，它也能工作。我知道，这更多的是对原始海报的评论，即插件无法解决他的问题。