Try this:
@Override
protected void onUserLeaveHint() {
if (!navigating) {
Intent intent2 = new Intent();
intent2.setClass(ActivityA.this, ActivityB.class);
intent2.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
forceHome(this, intent2);
}
super.onUserLeaveHint();
}
public static void forceHome(Context paramContext, Intent paramIntent) {
if (paramIntent != null) {
((AlarmManager) paramContext.getSystemService(ALARM)).set(1,
System.currentTimeMillis(),
PendingIntent.getActivity(paramContext, 0, paramIntent, 0));
}
}
As a security feature of android, the activity only launches after 5 seconds. If you want to launch it immediately. use your own Home Launcher
.