Wordpress排队风格不起作用

I'm making a custom wordpress theme, but for some reason the enqueue style is not working.

I've added:

<?php get_header(); ?> 

to the index.php

And i've added

<?php wp_head();?>  

Inside the head tag.

The following code is inside my functions.php:

function pompier_scripts() {
wp_enqueue_style( 'main-style', get_stylesheet_uri() );
wp_enqueue_style( 'bootstrap-style', get_template_directory_uri() .    '/css/bootstrap.min.css', array(), '1.0.0', false );


  //wp_enqueue_script( 'bootstrap-script', get_template_directory_uri() . '/js/bootstrap.min.js', array('jquery'), '1.0.0', false );


}

add_action( 'wp_enqueue_scripts', 'pompier_scripts' );

What am i missing here?

I don't know if this helps, but I just created my first child theme, and because It's based on a parent theme, I had to enqueue my custom stylesheet like this in order to make it work:

wp_enqueue_style( 'my-style', get_stylesheet_uri() . '/style.css' );