使用php下载excel文件后，它给出了错误

Question

I have made a file downloader here i am downloading the excel file it downloads successfully but when i open the file it gives me the error mention below Excel cannot open the file because the file format or file extension is not valid what is worng going on here

<?php

   if (isset($_POST['file_name'])) {

      $file_name = $_POST['file_name'];

      header('Content-type: application/octet-stream');
      header('Content-Disposition: attachment; filename="'.$file_name.'"');
     readfile('mystery_folder/'.$file_name);
    exit();
  }

 ?>

<form action="indexa.php" method="post" name="downloadform">

 <input name="file_name" value="My Tracker.xlsx" size="50" type="text">
<input type="submit" value="Download">

</form>

Answer 1

It's not a good idea to use a space in the filename:

value="My Tracker.xlsx"

It's probably not actually downloading the file, for lack of being able to find it. You should rename the file without the space.

Answer 2

Try to change Content-type:

application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

and add:

header('Content-Transfer-Encoding: binary');

This sample worked for me:

$file = 'sample.xlsx';
header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
header('Content-Disposition: attachment; filename='.basename($file));
header('Content-Transfer-Encoding: binary');
readfile(sprintf('./%s', $file));