How to update UI when an alarm broadcast receiver receive the event?

In my application there's a main activity which might be show on the top or in the background, and there's a broast receiver who receive the alarm event.

My main activity and the receiver seems to be two instances, and I can't call a static member in main activity (e.g.listview) to update itself from the receiver. It this correct?

So, how do i notify my current main activity to update itself?

p.s. I don't want to show my main activity开发者_开发问答 if it's not currently on top.

Thanks a lot.

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One mechanism I have seen used to provide a good solution is a Broadcast Receiver. You can read more about the solution in the Common Tasks area of the android documentation.

Edit: Although, rereading your question, I'm not positive I have enough information. If your receiver is already in your activity, then you just need to use the runOnUi(Runnable) call from the Activity to allow you to update the UI.