What is a Sticky Intent? [Android]

Question

I came across this term in the android documentation with the accompanying definition

These are broadcasts whose data is held by the system after being finished, so that clients can quickly retrieve that data without having to wait for the next broadcast.

What does it mean? Can someone elaborate its use with a particular example? I believe we have to request a permission for using this intent? Why so?

<uses-permission android:name="android.permission.BROADCAST_STICKY"/> - Allows an application to broadcast sticky intents.

Answer 1

Please read Mark Murphy's explanation here: http://stackoverflow.com/questions/2584497/what-is-the-difference-between-sendstickybroadcast-and-sendbroadcast-in-android

Heres an abstract example of how one might use a sticky broadcast:

Intent intent = new Intent("some.custom.action");
intent.putExtra("some_boolean", true);
sendStickyBroadcast(intent);

If you are listening for this broadcast in an Activity that was frozen (onPause), you could miss the actual event. This allows you to check the broadcast after it was fired (onResume).

EDIT: More on sticky boradcasts...

Also check out removeStickyBroadcast(Intent), and on API Level 5 +, isInitialStickyBroadcast() for usage in the Receiver's onReceive.

Hope that helps.