How to Show Notifications in Android Studio When the App is Closed

Learning how to show notifications in Android, even when your app is closed, can greatly enhance user experience and engagement. This guide will walk you through the process of setting up and displaying notifications using NotificationManager, BroadcastReceiver, and Service. Follow these detailed steps to ensure your app provides timely and relevant notifications to your users.

What You’ll Learn

In this guide, you will learn:

How to create a notification channel for Android 8.0 and above. How to create and manage notifications using NotificationManager. How to trigger notifications from a Service or BroadcastReceiver. Using AlarmManager to schedule notifications for specific times and intervals.

Step-by-Step Guide to Show Notifications in Android

Step 1: Set Up Your Notification Channel for Devices Running Android 8.0 and Above

To show notifications on modern Android devices, it's necessary to create a notification channel. Here's how:

public class MyApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        createNotificationChannel();
    }
    private void createNotificationChannel() {
        if (_INT > _CODES.O) {
            String name  My Notifications;
            String description  Channel for my notifications;
            int importance  _DEFAULT;
            NotificationChannel channel  new NotificationChannel(my_channel, name, importance);
            (description);
            NotificationManager notificationManager  getSystemService(_SERVICE);
            (channel);
        }
    }
}

Step 2: Create the Notification

To create a notification, use the class. Here’s an example method to demonstrate this:

public void showNotification(Context context, String title, String message) {
     builder  new (context, my_channel)
            .setSmallIcon(R.drawable.ic_notification) // Your notification icon
            .setContentTitle(title)
            .setContentText(message)
            .setPriority(_DEFAULT)
            .setContentIntent((context, 0, new Intent(context, ), 0))
            .setAutoCancel(true); // Automatically removes the notification when tapped
    NotificationManager notificationManager  (NotificationManager) (_SERVICE);
    (1, ());
}

Step 3: Trigger Notification from a Service or BroadcastReceiver

To show notifications when the app is closed, use either a Service or BroadcastReceiver. Here’s an example using a BroadcastReceiver:

public class NotificationReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        String title  (title);
        String message  (message);
        showNotification(context, title, message);
    }
}

Don’t forget to register your BroadcastReceiver in your AndroidManifest.xml:

receiver  /

Send a broadcast from anywhere in your app or from a background service:

Intent intent  new Intent(.ShowNotification);
intent.putExtra(title, Notification Title);
intent.putExtra(message, Notification Message);
sendBroadcast(intent);

Step 4: Use AlarmManager (Optional)

If you need to trigger notifications at specific intervals or times, consider using the AlarmManager:

AlarmManager alarmManager  (AlarmManager) getSystemService(_SERVICE);
Intent intent  new Intent(.ShowNotification);
intent.putExtra(title, Notification Title);
intent.putExtra(message, Notification Message);
PendingIntent pendingIntent  (this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
(AlarmManager.RTC_WAKEUP, ()   5000, pendingIntent); // Schedule for 5 seconds from now

Conclusion

By following these steps, you can effectively show notifications even when your app is closed. Make sure to handle permissions and background limitations as per the latest Android guidelines to ensure a smooth user experience.