broadcastreceiver - How to use Broadcast Receiver in different Applications in Android?

Question

I have here two applications in two different projects in eclipse. One application (A) defines an activity (A1) which is started first. Then i start from this activity the second activity (B1) in the second project (B). This works fine.

I start it the following way:

Intent intent = new Intent("pacman.intent.action.Launch");
intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
startActivity(intent);

Now i want to send intents bewtween the two activities by using broadcast receivers. In activity A1 i send the intents the following way:

Intent intent = new Intent("pacman.intent.action.BROADCAST");
intent.putExtra("message","Wake up.");
sendBroadcast(intent);

The part of the manifest file in activity A1 that is responsible for this broadcast is the following:

<activity android:name="ch.ifi.csg.games4blue.games.pacman.controller.PacmanGame" android:label="@string/app_name">
    <intent-filter>
       <action android:name="android.intent.action.MAIN" />
       <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>

    <intent-filter>
       <action android:name="android.intent.action.BROADCAST" />
    </intent-filter>
</activity>

In the receiving activity, I define the receiver the following way in the manifest file:

<application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".PacmanGame"
                  android:label="@string/app_name"
                  android:screenOrientation="portrait">
            <intent-filter>
                <action android:name="pacman.intent.action.Launch" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
            <receiver android:name="ch.ifi.csg.games4blue.games.pacman.controller.MsgListener" />
        </activity>

    </application>

The class message listener is implemented this way:

public class MsgListener extends BroadcastReceiver {

    /* (non-Javadoc)
     * @see android.content.BroadcastReceiver#onReceive(android.content.Context, android.content.Intent)
     */
    @Override
    public void onReceive(Context context, Intent intent) {
        System.out.println("Message at Pacman received!");
    }

}

Unfortunately, the message is never received. Although the method in activity A1 is called, i never receive an intent in B1.

Any hints how to solve this? Thanks a lot!

Answer 1

1. Your <receiver> element needs to be a peer of your <activity> element, not a child.
2. Your action string should NOT be in the android.intent.action namespace, unless you work for Google -- use ch.ifi.csg.games4blue.games.pacman.controller.BROADCAST or something like that instead
3. Your <intent-filter> with your custom action needs to be placed on the <receiver>, not the sending or receiving <activity>

See here for an example of implementing a manifest-registered broadcast receiver (for a system-broadcast Intent).