Problem with namespace and include

Question

Good morning. I have a webservice made on slimPHP . I have a class called control, and he belongs to the namespace controllers, it works normally without problems , but there arose the need to import a class for PDF manipulation , so that when I give the error include it , saying that it did not find the requested class. Does anyone know what it might be ? Follow the class.

<?php

 namespace controllers {

  include "fpdf/fpdf.php";


   class Control {

    //Atributo para banco de dados
    private $PDO;

    /*
      __construct
      Conectando ao banco de dados
     */

      function __construct() {
        $this->PDO = new \PDO('mysql:host=localhost;dbname=infoged', 'root', 
              '*******'); //Conexão
                  $this->PDO->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION); //habilitando erros do PDO
    }

    public function PDF($romaneio) {
       $pdf =  new \fpdf\FPDF("P", "pt", "A4");
       $pdf->AddPage();
    }
  }
 }

Error:

<b>Fatal error</b>:  Class 'fpdf\FPDF' not found in
<b>C:\xampp\htdocs\infoged\services\controllers\Control.php</b> on line
<b>142</b>

Archive start FPDF

 define('FPDF_VERSION', '1.81');


class FPDF {

    protected $page;               // current page number
    protected $n;                  // current object number
    protected $offsets;            // array of object offsets
    protected $buffer;             // buffer holding in-memory PDF
    protected $pages;      
 .....
 }

Answer 1

The correct form would be:

<?php namespace controllers; // Deve ser a primeira linha do arquivo e não se deve abrir chaves

include "fpdf/fpdf.php";

class Control {

    /*...*/

    public function PDF($romaneio) {
        // Classe está definida no escopo global, por isso se deve passar o \FPDF. Se tentar inicializar sem o \, é como se estivesse no escopo desse namespace, mas ela não está e por isso se deve chamar com \.
        $pdf =  new \FPDF("P", "pt", "A4");
        /*...*/
    }
}

Note: I have hidden unnecessary parts of the code to demonstrate only where to fix it. Make the change and see if it will work. If you want to call the class FPDF only instead of \FDPF, you should include in the archive fpdf/fpdf.php at the beginning of the file namespace controllers;.