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maui-local-notifications

Add local notifications to .NET MAUI apps on Android, iOS, and Mac Catalyst. Covers notification channels, permissions, scheduling, foreground/background handling, and DI registration. Works with XAML/MVVM, C# Markup, and MauiReactor. USE FOR: 'local notification', 'schedule notification', 'notification channel', 'notification permission', 'reminder notification', 'alert notification', 'in-app notification', 'foreground notification'. DO NOT USE FOR: push notifications from a server (use maui-push-notifications), permission handling only (use maui-permissions), or app lifecycle background tasks (use maui-app-lifecycle).

personAuthor: jakexiaohubgithub
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.NET MAUI Local Notifications

Implementation overview

  1. Define cross-platform INotificationManagerService interface and event args
  2. Implement Android notification service (channel, AlarmManager, BroadcastReceiver)
  3. Implement iOS/Mac Catalyst notification service (UNUserNotificationCenter)
  4. Register platform implementations via DI
  5. Configure platform permissions and MainActivity

See references/local-notifications-api.md for full implementation code.

Platform gotchas

Android

| Issue | Fix | |---|---| | Notifications silently fail on API 33+ | Must request POST_NOTIFICATIONS runtime permission first | | PendingIntent crash on Android 12+ | Must include PendingIntentFlags.Immutable for API 31+ | | Scheduled notifications lost on reboot | AlarmManager does not survive device restart — re-schedule on boot via BOOT_COMPLETED receiver | | No notification appears | Channel not created — required on API 26+ (Android 8.0) | | Notification tap doesn't return to app | LaunchMode = LaunchMode.SingleTop must be set on MainActivity |

// ✅ Correct — API 31+ requires Immutable flag
var pendingIntentFlags = (Build.VERSION.SdkInt >= BuildVersionCodes.S)
    ? PendingIntentFlags.CancelCurrent | PendingIntentFlags.Immutable
    : PendingIntentFlags.CancelCurrent;

// ❌ Wrong — crashes on Android 12+
var pendingIntentFlags = PendingIntentFlags.CancelCurrent;

iOS / Mac Catalyst

| Issue | Fix | |---|---| | No notification prompt appears | Permission already denied — user must re-enable in Settings | | Foreground notifications don't show | Must implement UNUserNotificationCenterDelegate and set Current.Delegate | | Notification shows Alert not Banner | Use UNNotificationPresentationOptions.Banner on iOS 14+ |

// ✅ iOS 14+ — use Banner
completionHandler(OperatingSystem.IsIOSVersionAtLeast(14)
    ? UNNotificationPresentationOptions.Banner
    : UNNotificationPresentationOptions.Alert);

// ❌ Always using Alert — deprecated on iOS 14+
completionHandler(UNNotificationPresentationOptions.Alert);

Windows

⚠️ Windows App SDK supports toast notifications but scheduled notifications are not yet supported. Immediate notifications work.

DI registration — platform-specific only

// ✅ Must use #if guards — there's no cross-platform implementation
#if ANDROID
    builder.Services.AddTransient<INotificationManagerService,
        Platforms.Android.NotificationManagerService>();
#elif IOS
    builder.Services.AddTransient<INotificationManagerService,
        Platforms.iOS.NotificationManagerService>();
#elif MACCATALYST
    builder.Services.AddTransient<INotificationManagerService,
        Platforms.MacCatalyst.NotificationManagerService>();
#endif

Common anti-patterns

// ❌ Sending without checking permission — silent failure on API 33+
notificationManager.SendNotification("Title", "Body");

// ✅ Request permission first
#if ANDROID
var status = await Permissions.RequestAsync<Platforms.Android.NotificationPermission>();
if (status != PermissionStatus.Granted) return;
#endif

// ❌ Updating UI directly from notification callback — cross-thread exception
notificationManager.NotificationReceived += (s, e) =>
    myLabel.Text = ((NotificationEventArgs)e).Title;

// ✅ Marshal to UI thread
notificationManager.NotificationReceived += (s, e) =>
    MainThread.BeginInvokeOnMainThread(() =>
        myLabel.Text = ((NotificationEventArgs)e).Title);

Decision framework

| Need | Approach | |---|---| | Immediate notification | SendNotification(title, message) with null notifyTime | | Scheduled reminder | SendNotification(title, message, DateTime.Now.AddMinutes(30)) | | Persist across reboot (Android) | Add BOOT_COMPLETED receiver to re-schedule alarms | | Rich notifications (images, actions) | Extend platform implementations with native APIs | | Push notifications from server | Use a different pattern entirely (FCM/APNs) |

Quick checklist

  • [ ] Cross-platform INotificationManagerService interface defined
  • [ ] Android: notification channel created (API 26+)
  • [ ] Android: POST_NOTIFICATIONS permission in manifest + runtime request (API 33+)
  • [ ] Android: PendingIntentFlags.Immutable used (API 31+)
  • [ ] Android: MainActivity has LaunchMode.SingleTop and handles OnNewIntent
  • [ ] iOS: UNUserNotificationCenterDelegate set for foreground display
  • [ ] iOS: Banner used instead of Alert on iOS 14+
  • [ ] DI registration uses #if platform guards
  • [ ] UI updates from notification callbacks use MainThread.BeginInvokeOnMainThread