WordPress Multisite 后台看不到各站点的ID，通过本插件可以实现鼠标放在站点上时，显示站点ID，插件代码：

    < ?php
    /*
    Plugin Name: Show Site ID
    Description: Show Site ID
    Version: 0.1
    Author: Ipstenu
    Author URI: http://www.ipstenu.org/
    This plugin is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
    This plugin is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.
    */
    function siteid_columns($column, $blog_id) {
    global $wpdb;
    if ( $column == 'site_id' ) {
    echo $blog_id;
    }
    return $value;
    }
    // Add in a column header
    function site_id($columns) {
    $columns['site_id'] = __('ID', 'site_id');
    return $columns;
    }
    add_filter( 'wpmu_blogs_columns', 'site_id' );
    add_action('manage_sites_custom_column', 'siteid_columns', 10, 3);
    add_action('manage_blogs_custom_column', 'siteid_columns', 10, 3);
    ?> 

新建个wpmulsiteid.php文件，把代码复制到文件中，上传到插件目录，启用即可。