Service progress updates

How can I get updates from a Service to an activity? For example, if I am downloading a file, I would like to show a progress bar in the activity. I don't want to use Asy开发者_开发问答ncTask (they only run while the activity is in focus, which is no good).

Many apps do this, so of course it is possible but finding an example is difficult.

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I usually send a BroadcastIntent and register a BroadcastReceiver in my Activity