Android Notification Guide
The notification system is a critical channel for user-app interaction on Android — it keeps users informed of important events even when the app is not in the foreground, such as incoming messages or calendar reminders. Notifications received a major overhaul in Android 4.1 (Jelly Bean) and continued to see refinements through Android 5.0 (Lollipop). Since 4.1, Android supports action buttons at the bottom of notifications, allowing users to perform common tasks directly without opening the app. Note: This article was written for the Android 4.1–5.0 era APIs. Starting from Android 8.0 (API 26), all notifications must be assigned to a Notification Channel. Android 13 (API 33) introduced the POST_NOTIFICATIONS runtime permission. The code examples below use NotificationCompat for backward compatibility; visual results may vary across devices. ...