WordPress修改自定义文章菜单图标

/**
 * Change Edit Posttype Icon in backend
 * freely adapted from http://wpsnipp.com/index.php/functions-php/change-custom-post-type-icon-for-new-and-edit-post-pages/
 * 
 * as an example we have used the "restaurant" Custom Post Type and icon, change line 9-11 to suit your post type and icon.
 */
function so_post_type_icon() {
    global $post_type;
    ?>
        <style>
            <?php if ( $post_type == 'restaurant' ) {
        ?>
                    .icon32-posts-restaurant {
            background: url( "<?php echo get_stylesheet_directory_uri() . '/images/ico_restaurant.png';?>" ) no-repeat center center transparent !important;
        }
        <?php
    }
    ?>
        </style>
    <?php
}
add_action( 'admin_head', 'so_post_type_icon' );
add_action( 'admin_head-post.php', 'so_post_type_icon' );
add_action( 'admin_head-post-new.php', 'so_post_type_icon' );