[Android Tips] 2. Disable recent apps dialog on long press home button

public void onWindowFocusChanged(boolean hasFocus) {
    super.onWindowFocusChanged(hasFocus);

            Log.d("Focus debug", "Focus changed !");

    if(!hasFocus) {
        Log.d("Focus debug", "Lost focus !");

        Intent closeDialog = new Intent(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
        sendBroadcast(closeDialog);
    }
}

该方法还可以禁止下拉状态栏