如何在插件菜单中如何使用WordPress默认的菜单图标

/**
 * 将菜单的图标设置为任何一个WordPress默认菜单图标
 *
 * @param 字符串 $menu_slug 是传递给 add_menu_page() 函数的菜单别名或链接
 * @param 字符串 $icon_class_name 是图标的 CSS 类，例如 "menu-icon-settings".
 * @return bool True if the menu was found and modified successfully, false otherwise.
 */
function set_menu_icon_class($menu_slug, $icon_class_name) {
    global $menu;

    $slug_index = 2;
    $css_class_index = 4;
    $icon_url_index = 6;

    foreach ($menu as $position => $item) {
        if ( $item[$slug_index] == $menu_slug ) {
            $item[$icon_url_index] = '';
            $item[$css_class_index] .= ' ' . $icon_class_name;

            $menu[$position] = $item;
            return true;
        }
    }

    return false;
}

function create_example_menu() {
    $menu_slug = 'example-menu';
    add_menu_page(
        'Example Menu',
        'Example Menu',
        'read',
        $menu_slug,
        '__return_null' //Will result in an empty page.
    );

    set_menu_icon_class($menu_slug, 'menu-icon-site');
});
add_action('admin_menu', 'create_example_menu');