使用FPDF在PHP中生成含多图PDF时遇致命错误求解决

你遇到的错误提示如下：

Notice: Undefined index: gambarvk_image in C:\xampp\htdocs\login\laporan_vk\laporanVK.php on line 821
Notice: Trying to access array offset on value of type null in C:\xampp\htdocs\login\laporan_vk\laporanVK.php on line 821
Notice: Undefined variable: gambarvk_image in C:\xampp\htdocs\login\laporan_vk\laporanVK.php on line 825
Fatal error: Uncaught Exception: FPDF error: Image file has no extension and no type was specified: ./uploaded_img/ in C:\xampp\htdocs\login\laporan_vk\laporanVK-fpdf\fpdf.php:267 Stack trace: #0 C:\xampp\htdocs\login\laporan_vk\laporanVK-fpdf\fpdf.php(881): FPDF->Error('Image file has ...') #1 C:\xampp\htdocs\login\laporan_vk\laporanVK.php(825): FPDF->Image('./uploaded_img/', 150, 25, 50, 20, '') #2 {main} thrown in C:\xampp\htdocs\login\laporan_vk\laporanVK-fpdf\fpdf.php on line 267.

手动修改路径后出现的错误：

Fatal error: Uncaught Exception: FPDF error: Unsupported image type: png/ in C:\xampp\htdocs\login\laporan_vk\laporanVK-fpdf\fpdf.php:267 Stack trace: #0 C:\xampp\htdocs\login\laporan_vk\laporanVK-fpdf\fpdf.php(889): FPDF->Error('Unsupported ima...') #1 C:\xampp\htdocs\login\laporan_vk\laporanVK.php(825): FPDF->Image('./uploaded_img....', 150, 25, 50, 20, 'png/') #2 {main} thrown in C:\xampp\htdocs\login\laporan_vk\laporanVK-fpdf\fpdf.php on line 267

问题根源 #

核心错误出在PDF生成的遍历逻辑：

1. 错误依赖表单提交时的$_FILES变量，生成PDF时该变量不存在，导致Undefined index
2. 未从数据库查询结果$row中获取图片文件名，误用了表单提交时的临时变量$gambarvk_image
3. 手动修改路径时把扩展名错误加到了文件夹名称里，导致路径和图片类型识别失败

修复后的完整代码 #

include 'config.php';

// 表单提交处理逻辑（建议后续改用预处理语句防SQL注入）
if(isset($_POST['add_gambarvk']))
{
  $gambarvk_name = $_POST['gambarvk_name'];
  $gambarvk_image = $_FILES['gambarvk_image']['name'];
  $gambarvk_image_tmp_name = $_FILES['gambarvk_image']['tmp_name'];
  $size = getimagesize($gambarvk_image_tmp_name);
  $gambarvk_image_folder = './uploaded_img/' . $gambarvk_image;

  if(empty($gambarvk_name) || empty($gambarvk_image))
  {
    $message[] = 'please fill out all';
  }
  else 
  {
    // 注意：此处存在SQL注入风险，建议替换为预处理语句
    $insert = "INSERT INTO gambarvk(name, image) VALUES('$gambarvk_name', '$gambarvk_image')";
    $upload = mysqli_query($conn,$insert);
  
    if($upload) 
    {
      move_uploaded_file($gambarvk_image_tmp_name, $gambarvk_image_folder);
      $message[] = 'Gambar berjaya dimasukkan';
    }
    else
    {
        $message[] = 'Gambar tidak berjaya dimasukkan';
    }
  }
};

$select = mysqli_query($conn, "SELECT * FROM gambarvk");

// 修复后的PDF图片生成逻辑
while($row = mysqli_fetch_assoc($select))
{
  // 从数据库行中获取存储的图片文件名
  $image_filename = $row['image'];
  // 从文件名提取格式，不再依赖$_FILES变量
  $image_format = strtolower(pathinfo($image_filename, PATHINFO_EXTENSION));  

  // 拼接正确的图片路径：文件夹 + 完整文件名
  $image_path = './uploaded_img/' . $image_filename;

  // 调用FPDF的Image方法
  $pdf->Image($image_path, 150, 25, 50, 20, $image_format);
}

关键修改说明 #

• 移除$_FILES依赖：生成PDF时，$_FILES仅在表单上传时存在，必须从数据库查询结果$row['image']获取已存储的文件名
• 正确提取图片格式：通过数据库中的文件名解析扩展名，避免依赖临时变量
• 修正路径拼接：路径格式为./uploaded_img/ + 完整文件名，不要将扩展名错误添加到文件夹名称中
• 可选安全优化：原插入语句存在SQL注入风险，建议替换为mysqli预处理语句：

  $insert = $conn->prepare("INSERT INTO gambarvk(name, image) VALUES(?, ?)");
  $insert->bind_param("ss", $gambarvk_name, $gambarvk_image);
  $upload = $insert->execute();
  

内容的提问来源于stack exchange，提问作者thir