How to check whether an activity is running or not [duplicate]

This question already has answers here: 开发者_StackOverflow Closed 10 years ago.

Possible Duplicate:

Check whether activity is active

I want to show a progress dialog on the screen if the activity is showing. But when the activity window is not showing, it will not do anything. Please suggest, how do I check whether my activity is showing or not?

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Thanks for quick responses.. but i think i figured my answer. I try-catched the part where i was starting the progress dialog.

Sample code --

try {
        pd2.show();
    } catch (WindowManager.BadTokenException e) {
        // TODO: handle exception
    } catch (Exception e) {
        // TODO: handle exception
    }

So if my activity is in on the top, it will show the progress dialog, otherwise it will throw a BadTokenException which is handled using try catch block.

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Read up on the Activity lifecycle. Specific methods get called based on your actvities current state, whether running, whether paused, killed, etc.