如何检查在WordPress后台中注册的用户数以及如何对用户注册时间进行排序

//用户注册时间排序
add_filter('manage_users_columns', function($column_headers){
    $column_headers['registered'] = '注册时间';
    return $column_headers;
});

add_filter('manage_users_custom_column', function($value, $column_name, $user_id){
    if($column_name=='registered'){
        $user = get_userdata($user_id);
        return get_date_from_gmt($user->user_registered);
    }else{
        return $value;
    }
},11,3);


add_filter('manage_users_sortable_columns', function($sortable_columns){
    $sortable_columns['reg_time'] = 'reg_time';
    return $sortable_columns;
});

add_action('pre_user_query', function($query){
    if(!isset($_REQUEST['orderby']) || $_REQUEST['orderby']=='reg_time' ){
        if( !in_array($_REQUEST['order'],array('asc','desc')) ){
            $_REQUEST['order'] = 'desc';
        }
        $query->query_orderby = "ORDER BY user_registered ".$_REQUEST['order']."";
    }
});