错误消息：

致命错误：未捕获错误：调用未定义的函数convert\\u to\\u screen（）/wp admin/includes/class wp list table。菲律宾比索：149

我的代码：

namespace ems\\apps\\admin;

if(!class_exists(\'\\WP_List_Table\')){
   require_once( ABSPATH.\'wp-admin/includes/class-wp-list-table.php\' ); 
}

class EmsListTable extends \\WP_List_Table{


  public function prepare_items(){

    $orderby = isset($_GET[\'orderby\']) ? trim($_GET[\'orderby\']):"" ;
    $order =  isset($_GET[\'order\']) ? trim($_GET[\'order\']):""  ;
    $search_data = isset($_POST[\'s\']) ? $_POST[\'s\']:"";

    $datas = $this->wp_list_table_data_sample($orderby,$order,$search_data);

    $perpage = 2 ;
    $curent_page = $this->get_pagenum();
    $totalitems = count($datas);
    $this->set_pagination_args(array(
      \'total_items\' => $totalitems,
      \'per_page\' => $perpage
    ));
    $this->items = array_slice($datas,(($curent_page - 1) * $perpage),$perpage); // $datas;

    $columns = $this->get_columns();
    $hidden = $this->get_hidden_columns();
    $shortable = $this->get_sortable_columns();
    $this->_column_headers =  array($columns,$hidden,$shortable);
  }
  /*
  * all data process
  */
  public function wp_list_table_data_sample($orderby=\'\',$order=\'\',$search_data=\'\'){
    global $wpdb;
    if (!empty($search_data)) {
      $allpost = $wpdb->get_results(
          "SELECT * FROM {$wpdb->posts}
          WHERE post_type=\'ems_events\'
          AND post_status=\'publish\'
          AND ( post_title LIKE \'%$search_data%\' OR post_content LIKE \'%$search_data%\' )"
      );
    }else{
      $allpost = get_posts(
        array(
          \'post_type\'   => \'ems_events\',
          \'post_status\' => \'publish\',
          \'orderby\'     => $orderby,
          \'order\'       => $order,
        )
      );
    }

    $post_array = array();

    if (count($allpost) > 0) {
      foreach ($allpost as $post) {
        // echo "<br>";
        // print_r($post);
        $post_array[] = array(
          "id"=>$post->ID,
          "title"=>$post->post_title,
          "content"=>$post->post_content,
          "name"=>$post->post_name,
        );
      }
    }

    return $post_array ;
  }
  /*hide some columns*/
  public function get_hidden_columns(){
    // return array(\'id\');
  }

  public function get_sortable_columns(){
    return array(
      "title"=>array("title",false),
      "name"=>array("name",false)
    );
  }

  public function get_bulk_actions(){
    $actions = array(
      "delete"=> "Delete",
      "edit"=> "Edit"
    );
    return   $actions;
  }


  /*register columns*/
  public function get_columns(){
    $columns = array(
      "cb" => "<input type=\'checkbox\' />",
      "id"=>"ID",
      "title"=>"Title",
      "content"=>"content",
      "name"=>"designation"
    );
    return $columns;
  }
  public function column_cb($id){
    return sprintf("<input type=\'checkbox\' name=\'post[]\' value=\'%s\' />" , $id);
  }
  // show columns
  public function column_default($item,$column_name){
    switch ($column_name) {
      case \'id\':
      case \'title\':
      case \'content\':
      case \'name\':
        return $item[$column_name];
      default:
        return "No Value";
    }
  }

  public function column_title($item){
    $action = array(
      "edit" => sprintf(\'<a href="?page=%s&action=%s&post_id=%s">Edit</a>\',$_GET[\'page\'],\'edit-koro\',$item[\'id\']),
      "delete" => sprintf(\'<a href="?page=%s&action=%s&post_id=%s">Delete</a>\',$_GET[\'page\'],\'delete-holo\',$item[\'id\']),
    );
    return sprintf(\'%1$s %2$s\',$item[\'title\'],$this->row_actions($action));
  }

}

use ems\\apps\\admin\\EventListTable as EventListTable;  

class EMS
{

    public function __construct()
    {
        $this->include_file();                                                                                                                                                    
    }
    public function include_file()
    {
        require_once(\'vendor/autoload.php\');

        new EventListTable();    
    }
}