FPDI类没有启动

I want to setup FPDI in my localhost but its gives me an error.

Fatal error: Class 'FPDF' not found in C:\wamp\www\book\fpdf_tpl.php on line 20

This is what I did:
I went to download page, I downloaded 2 packs (FPDF_TPL and FPDI) and unziped them into my localhost.
Then I made a example page:

<?php
    require_once('fpdf.php');
    require_once('fpdi.php');

    // initiate FPDI
    $pdf = new FPDI();

    // add a page
    $pdf->AddPage();

    // set the source file
    $pdf->setSourceFile("PdfDocument.pdf");

    // import page 1
    $tplIdx = $pdf->importPage(1);

    // use the imported page and place it at point 10,10 with a width of 100 mm
    $pdf->useTemplate($tplIdx, 10, 10, 100);

    // now write some text above the imported page
    $pdf->SetFont('Helvetica');
    $pdf->SetTextColor(255, 0, 0);
    $pdf->SetXY(30, 30);
    $pdf->Write(0, 'This is just a simple text');

    pdf->Output();

I did what the site says, but I had an error:

Fatal error: Class 'FPDF' not found in C:\wamp\www\book\fpdf_tpl.php on line 20

I have searched the error codes, but I can not figure it out.
Is there anybody experienced with FPDI ?

You have to download the library in the page Download and extract it to your folder. Then the code should work. Make sure you put the correct path for require_once.

download the fpdf lib from http://www.fpdf.org/en/download.php,

with the latest version fpdf17: require_once('your_dir/fpdf17/fpdf.php');

Add below line into your composer.

"require": {
        "setasign/fpdi-fpdf": "1.6.1"
    }

and update the composer using below code.

composer update setasign/fpdi-fpdf

Remove you require function lines and add below line. You will get an output.

include 'vendor/autoload.php';