我有一個代碼塊,只要擴展名為小寫jpg,就可以上傳圖像并創(chuàng)建縮略圖,但如果圖像是大寫的JPG,則不會上傳圖像.當(dāng)我重命名圖像時,例如example.JPG到example.jpg,它會上傳.但是example.JPG不會上傳,我沒有錯誤.這對我沒有任何意義.有沒有人對此有解釋？這是我的代碼：

<?php
function createThumbnail($filename) {
  require 'config.php';

  if(preg_match('/[.](jpg)$/', $filename)) {
    $im = imagecreatefromjpeg($filename.$path_to_image_directory);
  } else if (preg_match('/[.](gif)$/', $filename)) {
    $im = imagecreatefromgif($path_to_image_directory . $filename);
  } else if (preg_match('/[.](png)$/', $filename)) {
    $im = imagecreatefrompng($path_to_image_directory . $filename);
  }

  $ox = imagesx($im);
  $oy = imagesy($im);

  $nx = $final_width_of_image;
  $ny = $final_height_of_image;

  $nm = imagecreatetruecolor($nx, $ny);

  imagecopyresampled($nm, $im, 0,0,0,0,$nx,$ny,$ox,$oy);

  if(!file_exists($path_to_thumbs_directory)) {
    if(!mkdir($path_to_thumbs_directory)) {
       die("There was a problem. Please try again!");
    } 
  }

  imagejpeg($nm, $path_to_thumbs_directory . $filename);
  $tn = '<img src="' . $path_to_thumbs_directory . $filename . '" alt="image" />';
  $tn .= '<br />Congratulations. Your file has been successfully uploaded, and a      thumbnail has been created.';
  echo $tn;
}
?>

配置文件：

<?php  
$final_width_of_image = 300;
$final_height_of_image = 300;
$path_to_image_directory = '';
$path_to_thumbs_directory = '-tn';
?>     

解決方法:

在此代碼塊中,您只允許使用小寫文件擴展名：

if(preg_match('/[.](jpg)$/', $filename)) {
//--lowercase-only--^ 
    $im = imagecreatefromjpeg($filename.$path_to_image_directory);
}else if (preg_match('/[.](gif)$/', $filename)) {
    $im = imagecreatefromgif($path_to_image_directory . $filename);
} else if (preg_match('/[.](png)$/', $filename)) {
    $im = imagecreatefrompng($path_to_image_directory . $filename);
}

您可以通過在正則表達(dá)式中放置一個OR condition來修復(fù)：

if(preg_match('/[.](jpg|JPG)$/', $filename)) {
// -----uppercase-------^
    $im = imagecreatefromjpeg($filename.$path_to_image_directory);
}else if (preg_match('/[.](gif|GIF)$/', $filename)) {
    $im = imagecreatefromgif($path_to_image_directory . $filename);
} else if (preg_match('/[.](png|PNG)$/', $filename)) {
    $im = imagecreatefrompng($path_to_image_directory . $filename);
}

或者您可以使用i修飾符添加不區(qū)分大小寫：

if(preg_match('/[.](jpg)$/i', $filename)) {
// -------modifier--------^ 
    $im = imagecreatefromjpeg($filename.$path_to_image_directory);
}else if (preg_match('/[.](gif)$/i', $filename)) {
    $im = imagecreatefromgif($path_to_image_directory . $filename);
} else if (preg_match('/[.](png)$/i', $filename)) {
    $im = imagecreatefrompng($path_to_image_directory . $filename);
}