A simple wrapper of Unity Mobile Notifications.

MobileLocalNotification.cs

using System;
#if UNITY_ANDROID
using Unity.Notifications.Android;
#elif UNITY_IOS
using UnityEngine.iOS;
using CalendarUnit = UnityEngine.iOS.CalendarUnit;
using LocalNotification = UnityEngine.iOS.LocalNotification;
using NotificationServices = UnityEngine.iOS.NotificationServices;
#endif
using UnityEngine;

namespace Game.Util
{
    interface ILocalNotification
    {
        void SendNotification(string title, string content, DateTime triggerTime, TimeSpan? interval = null);
        void ClearAllDisplayedNotifications();
        void CancelAllNotifications();
    }
    
#if UNITY_ANDROID
    public class AndroidLocalNotification : ILocalNotification
    {
        readonly string _smallIcon;
        readonly string _largeIcon;
        readonly string _channelId;
        
        public AndroidLocalNotification(
            string channelId,
            string channelName,
            string smallIcon,
            string largeIcon)
        {
            _channelId = channelId;
            _smallIcon = smallIcon;
            _largeIcon = largeIcon;
            var channel = new AndroidNotificationChannel
            {
                Id = channelId,
                Name = channelName,
                Description = "Default channel",
                Importance = Importance.High,
                LockScreenVisibility = LockScreenVisibility.Public,
                EnableVibration = true,
                CanShowBadge = true
            };    
            
            AndroidNotificationCenter.RegisterNotificationChannel(channel);
        }
        
        public void SendNotification(string title, string content, DateTime triggerTime, TimeSpan? interval = null)
        {
            var notification = new AndroidNotification
            {
                Title = title,
                Text = content,
                FireTime = triggerTime,
                SmallIcon = _smallIcon,
                LargeIcon = _largeIcon
            };

            if (interval != null)
            {
                notification.RepeatInterval = interval.Value;
            }

            AndroidNotificationCenter.SendNotification(notification, _channelId);
        }

        public void ClearAllDisplayedNotifications()
        {
            AndroidNotificationCenter.CancelAllDisplayedNotifications();
        }

        public void CancelAllNotifications()
        {
            AndroidNotificationCenter.CancelAllNotifications();
        }
    }
#endif
    
#if UNITY_IOS
    public class IosLocalNotification : ILocalNotification
    {
        public IosLocalNotification()
        {
            NotificationServices.RegisterForNotifications(NotificationType.Alert |
                                                          NotificationType.Badge |
                                                          NotificationType.Sound);    
        }
        
        /// <summary>
        /// 受api限制，如果是repeat模式，会忽略interval值，直接每天repeat
        /// </summary>
        /// <param name="title"></param>
        /// <param name="content"></param>
        /// <param name="triggerTime"></param>
        /// <param name="interval"></param>
        public void SendNotification(string title, string content, DateTime triggerTime, TimeSpan? interval = null)
        {
            var notification = new LocalNotification
            {
                fireDate = triggerTime,
                alertBody = content,
                applicationIconBadgeNumber = 1,
                soundName = LocalNotification.defaultSoundName
            };

            if (interval != null)
            {
                if (interval.Value.Days >= 1)
                {
                    notification.repeatInterval = CalendarUnit.Day;
                }
                else if (interval.Value.Hours >= 1)
                {
                    notification.repeatInterval = CalendarUnit.Hour;
                } 
                else if (interval.Value.Minutes >= 1)
                {
                    notification.repeatInterval = CalendarUnit.Minute;
                }
            }
            
            NotificationServices.ScheduleLocalNotification(notification);
        }

        public void ClearAllDisplayedNotifications()
        {
            NotificationServices.ClearLocalNotifications();
        }

        public void CancelAllNotifications()
        {
            NotificationServices.CancelAllLocalNotifications();
        }
    }
#endif
    
#if UNITY_EDITOR
    public class EditorLocalNotification : ILocalNotification
    {
        public void SendNotification(string title, string content, DateTime triggerTime, TimeSpan? interval = null)
        {
            Debug.Log($"{nameof(SendNotification)}--{title}--{content}--{triggerTime}--{interval}");
        }

        public void ClearAllDisplayedNotifications()
        {
            Debug.Log(nameof(ClearAllDisplayedNotifications));
        }

        public void CancelAllNotifications()
        {
            Debug.Log(nameof(CancelAllNotifications));
        }
    }
#endif

    public class MobileLocalNotification : ILocalNotification
    {
        readonly ILocalNotification _localNotification;
        
        public MobileLocalNotification()
        {
#if UNITY_EDITOR
            _localNotification = new EditorLocalNotification();
#elif UNITY_ANDROID
            string channelId = "channel_id";
            _localNotification = new AndroidLocalNotification(channelId, Application.productName, "small", "large");
#elif UNITY_IOS
            _localNotification = new IosLocalNotification();
#endif
        }

        public void SendNotification(string title, string content, DateTime triggerTime, TimeSpan? interval = null)
        {
            _localNotification.SendNotification(title, content, triggerTime, interval);
        }

        public void ClearAllDisplayedNotifications()
        {
            _localNotification.ClearAllDisplayedNotifications();
        }

        public void CancelAllNotifications()
        {
            _localNotification.CancelAllNotifications();
        }
    }
}