docs/html/training/notify-user/build-notification.jd

page.title=Building a Notification
parent.title=Notifying the User
parent.link=index.html

trainingnavtop=true
next.title=Preserving Navigation when Starting an Activity
next.link=navigation.html

@jd:body

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<h2>This lesson teaches you to</h2>
<ol>
  <li><a href="#builder">Create a Notification Builder</a></li>
  <li><a href="#action">Define the Notification's Action</a></li>
  <li><a href="#click">Set the Notification's Click Behavior</a></li>
  <li><a href="#notify">Issue the Notification</a></li>
</ol>

<!-- other docs (NOT javadocs) -->
<h2>You should also read</h2>

<ul>
    <li>
        <a href="{@docRoot}guide/topics/ui/notifiers/notifications.html">Notifications</a> API Guide
    </li>
    <li>
        <a href="{@docRoot}guide/components/intents-filters.html">
        Intents and Intent Filters
        </a>
    </li>
    <li>
        <a href="{@docRoot}design/patterns/notifications.html">Notifications</a> Design Guide
    </li>
</ul>


</div>
</div>


<p>This lesson explains how to create and issue a notification.</p>

<p>The examples in this class are based on the 
{@link android.support.v4.app.NotificationCompat.Builder} class. 
{@link android.support.v4.app.NotificationCompat.Builder} 
is in the <a href="{@docRoot}">Support Library</a>. You should use
{@link android.support.v4.app.NotificationCompat} and its subclasses,
particularly {@link android.support.v4.app.NotificationCompat.Builder}, to
provide the best notification support for a wide range of platforms. </p>

<h2 id="builder">Create a Notification Builder</h2>

<p>When creating a notification, specify the UI content and actions with a 
{@link android.support.v4.app.NotificationCompat.Builder} object. At bare minimum, 
a {@link android.support.v4.app.NotificationCompat.Builder Builder} 
object must include the following:</p>

<ul>
  <li>
        A small icon, set by
        {@link android.support.v4.app.NotificationCompat.Builder#setSmallIcon setSmallIcon()}
    </li>
    <li>
        A title, set by
        {@link android.support.v4.app.NotificationCompat.Builder#setContentTitle setContentTitle()}
    </li>
    <li>
        Detail text, set by
        {@link android.support.v4.app.NotificationCompat.Builder#setContentText setContentText()}
    </li>
</ul>
<p> For example: </p>
<pre>
NotificationCompat.Builder mBuilder =
    new NotificationCompat.Builder(this)
    .setSmallIcon(R.drawable.notification_icon)
    .setContentTitle(&quot;My notification&quot;)
    .setContentText(&quot;Hello World!&quot;);
</pre>

<h2 id="action">Define the Notification's Action</h2>


<p>Although actions are optional, you should add at least one action to your
notification. An action takes users directly from the notification to an
{@link android.app.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 {@link android.app.PendingIntent} containing an {@link
android.content.Intent} that starts an {@link android.app.Activity} in your
application.</p>

<p>How you construct the {@link android.app.PendingIntent} depends on what type
of {@link android.app.Activity} you're starting. When you start an {@link
android.app.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 
<a href="navigation.html">Preserving Navigation when Starting an Activity</a> for
more information):</p>

<pre>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
);
</pre>

<h2 id="click">Set the Notification's Click Behavior</h2>

<p>
To associate the {@link android.app.PendingIntent} created in the previous
step with a gesture, call the appropriate method of {@link
android.support.v4.app.NotificationCompat.Builder}. For example, to start an
activity when the user clicks the notification text in the notification drawer,
add the {@link android.app.PendingIntent} by calling {@link
android.support.v4.app.NotificationCompat.Builder#setContentIntent
setContentIntent()}. For example:</p>

<pre>PendingIntent resultPendingIntent;
...
mBuilder.setContentIntent(resultPendingIntent);</pre>

<h2 id="notify">Issue the Notification</h2>

<p>To issue the notification:</p>
<ul>
<li>Get an instance of {@link android.app.NotificationManager}.</li> 

<li>Use the {@link android.app.NotificationManager#notify notify()} method to issue the
notification. When you call {@link android.app.NotificationManager#notify notify()}, specify a notification ID. 
You can use this ID to update the notification later on. This is described in more detail in 
<a href="managing.html">Managing Notifications</a>.</li>

<li>Call {@link
android.support.v4.app.NotificationCompat.Builder#build() build()}, which
returns a {@link android.app.Notification} object containing your
specifications.</li>

<p>For example:</p>

<pre>
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());
</pre>