This lesson teaches you to
- Create a Notification Builder
- Define the Notification's Action
- Set the Notification's Click Behavior
- Issue the Notification
You should also read
- Notifications API Guide
- Intents and Intent Filters
- Notifications Design Guide
This lesson explains how to create and issue a notification.
The examples in this class are based on the
NotificationCompat.Builder
class.
NotificationCompat.Builder
is in the Support Library. You should use
NotificationCompat
and its subclasses,
particularly NotificationCompat.Builder
, to
provide the best notification support for a wide range of platforms.
Create a Notification Builder
When creating a notification, specify the UI content and actions with a
NotificationCompat.Builder
object. At bare minimum,
a Builder
object must include the following:
-
A small icon, set by
setSmallIcon()
-
A title, set by
setContentTitle()
-
Detail text, set by
setContentText()
For example:
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this) .setSmallIcon(R.drawable.notification_icon) .setContentTitle("My notification") .setContentText("Hello World!");
Define the Notification's Action
Although actions are optional, you should add at least one action to your
notification. An action takes users directly from the notification to an
Activity
in your application, where they can look at the
event that caused the notification or do further work. Inside a notification, the action itself is
defined by a PendingIntent
containing an Intent
that starts an Activity
in your
application.
How you construct the PendingIntent
depends on what type
of Activity
you're starting. When you start an Activity
from a notification, you must preserve the user's expected
navigation experience. In the snippet below, clicking the notification opens a
new activity that effectively extends the behavior of the notification. In this
case there is no need to create an artificial back stack (see
Preserving Navigation when Starting an Activity for
more information):
Intent resultIntent = new Intent(this, ResultActivity.class); ... // Because clicking the notification opens a new ("special") activity, there's // no need to create an artificial back stack. PendingIntent resultPendingIntent = PendingIntent.getActivity( this, 0, resultIntent, PendingIntent.FLAG_UPDATE_CURRENT );
Set the Notification's Click Behavior
To associate the PendingIntent
created in the previous
step with a gesture, call the appropriate method of NotificationCompat.Builder
. For example, to start an
activity when the user clicks the notification text in the notification drawer,
add the PendingIntent
by calling setContentIntent()
. For example:
PendingIntent resultPendingIntent; ... mBuilder.setContentIntent(resultPendingIntent);
Issue the Notification
To issue the notification:
- Get an instance of
NotificationManager
. - Use the
notify()
method to issue the notification. When you callnotify()
, specify a notification ID. You can use this ID to update the notification later on. This is described in more detail in Managing Notifications. - Call
build()
, which returns aNotification
object containing your specifications.
For example:
NotificationCompat.Builder mBuilder; ... // Sets an ID for the notification int mNotificationId = 001; // Gets an instance of the NotificationManager service NotificationManager mNotifyMgr = (NotificationManager) getSystemService(NOTIFICATION_SERVICE); // Builds the notification and issues it. mNotifyMgr.notify(mNotificationId, mBuilder.build());