How do I bring an existing activity back to the front from a service?

Question

I have a background service which is running and I am using a notification and a PendingIntent to allow the user to "reopen" the existing home activiy. Unfortunately what's happening is that it's creating a new home activity stacked on top of the one I want to go to meaning that the user has to hit the back button to get back to the original one. What do I have to change in the following service code to ensure it simply reopens the existing Activity?

    Intent notificationIntent = new Intent(ApplicationContext, typeof( MainActivity ) );
    notificationIntent.SetFlags (ActivityFlags.NewTask);
    PendingIntent pendingIntent = PendingIntent.GetActivity(this, 0, notificationIntent, 0 );
    Notification notification = new Notification (Resource.Drawable.Icon, "Playing: " + mStreamName );
    notification.Flags |= NotificationFlags.OngoingEvent;

    notification.SetLatestEventInfo (this, "MyApp", "Announcement!", pendingIntent);
    StartForeground((int)NotificationFlags.ForegroundService, notification);

My manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="..." android:versionCode="2" android:versionName="2.0">
<uses-sdk />
<application android:label="..." android:icon="@drawable/icon">
        <service android:enabled="true" android:name=".AudioService"/>
</application>
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.WAKE_LOCK" />
</manifest>

If you launch your app for the first time either from the installer, browser or an IDE (IntelliJ, Eclipse, Android Studio, etc.) ou may actually be seeing this long-standing Android bug: http://stackoverflow.com/a/16447508/769265 — David Wasser, Jun 23 '14 at 14:50
David, I get the same effect launching from within Android on the device. — screenglow, Jun 24 '14 at 01:38
Your manifest includes no activities. Please post the complete manifest — David Wasser, Jun 24 '14 at 08:54
That *was* the complete manifest until I added the activity below. — screenglow, Jun 24 '14 at 14:57
Well, that can't be right. You didn't have your `MainActivity` in the manifest at all? — David Wasser, Jun 25 '14 at 07:00

score 0 · Answer 1 · answered Jun 23 '14 at 03:32

0

you might give your activity a "single top" flag, and handle relaunch stuff in your OnNewIntent. You can refer to http://developer.android.com/reference/android/app/Activity.html#onNewIntent(android.content.Intent)

answered Jun 23 '14 at 03:32

jobcrazy

1,073
10
16

I tried that. Added the flag using intent.SetFlags( ActivityFlags.SingleTop ) from both original StartActivity() call and the notification's PendingIntent and neither seemed to have any effect. – screenglow Jun 24 '14 at 01:49

score 0 · Accepted Answer · edited May 23 '17 at 12:10

I found an answer though I can't explain why this works or what the difference is. If anyone would care to elaborate on what this changes, I'd appreciate actually understanding it.

Adding the following lines manually to my manifest file solved the problem:

<activity android:name="MainActivity"
          android:label="@string/app_name">
    <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
    </intent-filter>
</activity>

It was suggested here in an answer which was never accepted:

How to bring Android existing activity to front via notification

How do I bring an existing activity back to the front from a service?

2 Answers2