Bootstrap css not getting applied to the custom Wordpress Dashboard Widget

Question

I am facing difficulty applying Bootstrap to my custom dashboard widget.

function admin_theme_style() {
    if( is_admin() ) {
        wp_enqueue_script('bootstrap-script', plugin_dir_url($this->_FILE_) . 'includes/js/bootstrap.min.js');
        wp_enqueue_script('jquery-ui-core', false, array('jquery'));
        wp_enqueue_script('google-platform', '//apis.google.com/js/platform.js', array('jquery'));
        wp_enqueue_style('webinar', plugin_dir_url($this->_FILE_) . 'includes/css/webinar.css');
        wp_enqueue_style('bootstrap', plugin_dir_url($this->_FILE_) . 'includes/css/bootstrap.css');    
    }

}
add_action('admin_enqueue_scripts', array($this,'admin_theme_style');

For the plugin, scripts and CSS gets loaded correctly.

Answer 1

Well, the add_action() should be

add_action( string $tag, callable $function_to_add, int $priority = 10, 
            int $accepted_args = 1 ) 

You've got the tag and then you have an array. That array should just be a string of 'admin_theme_style'. That should call the entire function.

add_action()

Simply try:

add_action('admin_enqueue_scripts', 'admin_theme_style');