Android: How to Resume Application/Activity from BroadcastReceiver?

问题

If my procedure is following:

1. Launch Activity A -> Activity B
2. Press 'Home' button.
3. Click on the application again.

Result: 'Activity B' shows up (it resumes).

1. Launch Activity A -> Activity B
2. Press 'Back' button.
3. Click on the application again.

Result: 'Activity A' shows up (it restarts).

I want to do exactly same from the BroadcastReceiver.

1. Launch Activity A -> Activity B
2. Press 'Home' button.
3. BroadcastReceiver receives a broadcast and want to "resume" application.

My expected result: 'Activity B' shows up.

I want to do exactly same from the BroadcastReceiver.

1. Launch Activity A -> Activity B
2. Press 'Back' button.
3. BroadcastReceiver receives a broadcast and want to "restart" application.

Current result: 'Activity A' shows up.

Following code doesn't do what I expect:

public void onReceive(Context context, Intent intent) {
        Intent i = new Intent(context, ActivityA.class);
        i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(i);
    }

I also tried "Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY" but no luck.

回答1:

My gosh, I made it working!!

Thank you for other answers you guys provided, but they weren't what I was looking for.

This will do the job:

Intent i = getPackageManager().getLaunchIntentForPackage("com.your.package.name");
i.setFlags(0);
i.setPackage(null);
startActivity(i);

回答2:

check out this

set flags to your intent Intent.FLAG_ACTIVITY_REORDER_TO_FRONT and

Intent.FLAG_ACTIVITY_NEW_TASK as following

intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT|Intent.FLAG_ACTIVITY_NEW_TASK);

来源：https://stackoverflow.com/questions/9881976/android-how-to-resume-application-activity-from-broadcastreceiver