최상위 Activity 확인

퍼미션

<uses-permission android:name="android.permission.GET_TASKS"/>

코드

ActivityManager am = (ActivityManager)getSystemService(Context.ACTIVITY_SERVICE);

List<ActivityManager.RunningTaskInfo> Info = am.getRunningTasks(1);

ComponentName topActivity = Info.get(0).topActivity;

String activityname = topActivity.getPackageName();