Android How to - Display Notifications

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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 ww.  j  a v  a2 s .  c  om*/
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 w w w  .  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.

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