[PROS] A Little Question about LVGL

This is my open source code for graphical interfaces.
I want to complete a graphics library of lvgl for pros user, but my level is too poor.

I created a button array with lv_btnm_create().
code:
1.png
pic:
IMG_20181122_233957.jpg

But when you click any button to go in, it will turn into a blue background and I can’t inherit “lv_theme_alien”.
I can’t use lv_obj_set_style to modify the color, either.
IMG_20181122_234111.jpg

What is your question?

1 I can’t get the title pointer of “obj_win” or"obj_tabview"" and I want to set its size.
The default title is too high and takes up a lot of space.
2 I want to create a universal exit button

I get the parent pointer of the incoming parameter btn, which I set to nullptr, but in fact the parent pointer does not point to nullptr. I have a std:: array < lv_obj_t*> obj to manage all my pages and he will judge obj== nullptr to call the lv_obj_del() function.

1.png
3.png