Using the Notification Manager in Android
This article describes how to use the Notification Manager in Android. It is based on Eclipse 4.2, Java 1.6 and Android 4.2.
Table of Contents
The following assumes that you have already basic knowledge in Android development. Please check the Android development tutorial to learn the basics.
Android allows to put notification into the titlebar of your application. The user can expand the notification bar and by selecting the notification the user can trigger another activity.
Notifications in Android are represented by the
Notification
class. To create notifications you use the NotificationManager
class which can be received from the Context
, e.g. an activity or aservice, via the getSystemService()
method.NotificationManager notificationManager = (NotificationManager)
getSystemService(NOTIFICATION_SERVICE);
The
Notification.Builder
provides an builder interface to create an Notification
object. You use a PendingIntent
to specify the action which should be performed once the user select the notification.The
Notification.Builder
allows you to add up too three buttons with definable actions to the notification.// prepare intent which is triggered if the
// notification is selected
Intent intent = new Intent(this, NotificationReceiver.class);
PendingIntent pIntent = PendingIntent.getActivity(this, 0, intent, 0);
// build notification
// the addAction re-use the same intent to keep the example short
Notification n = new Notification.Builder(this)
.setContentTitle("New mail from " + "test@gmail.com")
.setContentText("Subject")
.setSmallIcon(R.drawable.icon)
.setContentIntent(pIntent)
.setAutoCancel(true)
.addAction(R.drawable.icon, "Call", pIntent)
.addAction(R.drawable.icon, "More", pIntent)
.addAction(R.drawable.icon, "And more", pIntent).build();
NotificationManager notificationManager =
(NotificationManager) getSystemService(NOTIFICATION_SERVICE);
notificationManager.notify(0, n);
Android 4.1 supports expandable notifications. In addition to normal notification view it is possible to define a big view which gets shown when notification is expanded. There are three styles to be used with the big view: big picture style, big text style, Inbox style. The following code demonstrates the usage of the
BigTextStyle()
which allows to use up to 256 dp.String longText = "...";
Notification noti = new Notification.Builder(this).
.....
.setStyle(new Notification.BigTextStyle().bigText(longText))
The user can dismiss all notification or if you set your notification to auto-cancel it is also removed once the user selects it.
You can also call the
cancel()
for a specific notification ID on the NotificationManager
. ThecancelAll()
method call removes all of the notifications you previously issued.A PendingIntent is a token that you give to another application (e.g. Notification Manager, Alarm Manager or other 3rd party applications), which allows this other application to use the permissions of your application to execute a predefined piece of code.
To perform a broadcast via a pending intent so get a PendingIntent via the
getBroadcast()
method of the PendingIntent
class. To perform an activity via an pending intent you receive the activity viaPendingIntent.getActivity()
.Create a new project called de.vogella.android.notificationmanager with the activity class called
CreateNotificationActivity
. This activity should use the main.xml
layout file.<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:onClick="createNotification"
android:text="Create Notification" >
</Button>
</LinearLayout>
Create the following
result.xml
layout file.<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="This is the result activity opened from the notification" >
</TextView>
</LinearLayout>
Create a new activity called NotificationReceiverActivity with the following coding. Don't forget to register the activity in the
AndroidManfest.mf
.package de.vogella.android.notificationmanager;
import android.app.Activity;
import android.os.Bundle;
public class NotificationReceiverActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.result);
}
}
Change the
CreateNotificationActivity
class to the following coding.package de.vogella.android.notificationmanager;
import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class CreateNotificationActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void createNotification(View view) {
// Prepare intent which is triggered if the
// notification is selected
Intent intent = new Intent(this, NotificationReceiverActivity.class);
PendingIntent pIntent = PendingIntent.getActivity(this, 0, intent, 0);
// Build notification
// Actions are just fake
Notification noti = new Notification.Builder(this)
.setContentTitle("New mail from " + "test@gmail.com")
.setContentText("Subject").setSmallIcon(R.drawable.icon)
.setContentIntent(pIntent)
.addAction(R.drawable.icon, "Call", pIntent)
.addAction(R.drawable.icon, "More", pIntent)
.addAction(R.drawable.icon, "And more", pIntent).build();
NotificationManager notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
// hide the notification after its selected
noti.flags |= Notification.FLAG_AUTO_CANCEL;
notificationManager.notify(0, noti);
}
}
Run your application and press the button. A new notification is created. If you select it your second activity will be displayed.
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