Display Notifications
Description
The following code shows how to use the NotificationManager to display a persistent message at the top of the device, commonly known as the status bar.
Example
Add the following statements in bold to the AndroidManifest.xml file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="net.learn2develop.Notifications"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="14" />
<uses-permission android:name="android.permission.VIBRATE"/>
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:label="@string/app_name"
android:name=".NotificationsActivity" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".NotificationView"
android:label="Details of notification">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>
</manifest>
Add the following statements to the main layut xml file:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button
android:id="@+id/btn_displaynotif"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Display Notification"
android:onClick="onClick"/>
</LinearLayout>
Add the following statements to the MainActivity.java file:
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;
//from w w w . j a va2 s . co m
public class MainActivity extends Activity {
int notificationID = 1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void onClick(View view) {
displayNotification();
}
protected void displayNotification()
{
Intent i = new Intent(this, NotificationView.class);
i.putExtra("notificationID", notificationID);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, i, 0);
NotificationManager nm = (NotificationManager)
getSystemService(NOTIFICATION_SERVICE);
Notification notif = new Notification(
R.drawable.ic_launcher,
"Reminder: Meeting starts in 5 minutes",
System.currentTimeMillis());
CharSequence from = "System Alarm";
CharSequence message = "Buzz at 3pm...";
notif.setLatestEventInfo(this, from, message, pendingIntent);
//---100ms delay, vibrate for 250ms, pause for 100 ms and
// then vibrate for 500ms---
notif.vibrate = new long[] { 100, 250, 100, 500};
nm.notify(notificationID, notif);
}
}
Populate the SecondActivity.java file as follows
import android.app.Activity;
import android.app.NotificationManager;
import android.os.Bundle;
/*from www . j a v a 2 s . c o m*/
public class SecondActivity extends Activity
{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.notification);
NotificationManager nm = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
nm.cancel(getIntent().getExtras().getInt("notificationID"));
}
}
Populate the notification.xml file as follows:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Here are the details for the notification..." />
</LinearLayout>
Note
A PendingIntent object helps you to perform an action on your application's behalf, often at a later time, regardless of whether your application is running or not.