ActivityManager am = (ActivityManager) getSystemService(ACTIVITY_SERVICE); List<ActivityManager.RecentTaskInfo> recentTasks = am.getRecentTasks(10, ActivityManager.RECENT_WITH_EXCLUDED);you need add <uses-permission android:name="android.permission.GET_TASKS"/> in your manifext
List<ActivityManager.RecentTaskInfo> recentTasks = am.getRecentTasks(10, ActivityManager.RECENT_WITH_EXCLUDED);you need add <uses-permission android:name="android.permission.GET_TASKS"/> in your manifext