注意：Undefined index: $error in C:\wamp\www\btb_sandbox\upload_2.php on line 35

Question

我遇到了下面所述的这种错误，我对此并不完全理解。如果我在没有选择文件的情况下按下上传按钮！

注意：未定义索引：第 35 行 C:\wamp\www\btb_sandbox\upload_2.php 中的 $error

<?php
 // In an application, this could be moved to a config file
 $upload_errors = array(
    // http://www.php.net/manual/en/features.file_upload.errors.php
    UPLOAD_ERR_OK           => "No errors.",
    UPLOAD_ERR_INI_SIZE     => "Larger than upload_max_filesize.",
    UPLOAD_ERR_FORM_SIZE    => "Larger than form MAX_FILE_SIZE.",
    UPLOAD_ERR_PARTIAL      => "Partial upload.",
    UPLOAD_ERR_NO_FILE      => "No file.",
    UPLOAD_ERR_NO_TMP_DIR   => "No temporary directory.",
    UPLOAD_ERR_CANT_WRITE   => "Can't write to disk.",
    UPLOAD_ERR_EXTENSION    => "File upload stopped by extension."
 );
if(isset($_POST['submit']))
{
    // process the form data
    $tmp_file = $_FILES['file_upload']['tmp_name'];
    $target_file = basename($_FILES['file_upload']['name']);
    $upload_dir = "uploads";

    // You will probably want to first use file_exists() to
    // make sure there isn't already a file by the same name

    // move_uploaded_file will return false if $tmp_file is
    // not a valid upload file or if it cannot be moved for
    // any same name
    if(isset($_FILES['file_upload']) || isset($_FILES['file_upload']['error']))
    {

if(move_uploaded_file($tmp_file, $upload_dir."/".$target_file)) 
{
    $message = "File uploaded successfully.";
} else {
     $error = $_FILES['file_upload']['error'];
     $message =  $upload_errors['$error'];
    // echo "<pre>";
    // print_r($_FILES['file_upload']);
    // echo "</pre>";
    // echo "<hr />";

    }
    }
}
?>
<html>
    <head>
        <title>Upload</title>
    </head>
    <body>

<?php
// The maximum file size (in bytes) must be declared before the file input field
// and can't be larger than the setting for upload_max_filesize in php.ini.
//
// This form value can be manipulated. You should still use it, but you rely 
// on upload_max_filesize as the absolute limit.
//
// Think of it as a polite declaration: "Hey PHP, here comes a file less than X..."
// PHP will stop and complain once X is exceeded.
// 
// 1 megabyte is actually 1,048,576 bytes.
// You can round it unless the precision matters.
?>

        <?php if(!empty($message)) { echo "<p>{$message}</p>"; } ?>
        <form action="upload_2.php" enctype="multipart/form-data" method="POST">

          <input type="hidden" name="MAX_FILE_SIZE" value="1000000" />
          <input type="file" name="file_upload" />

          <input type="submit" name="submit" value="Upload" />
        </form>

    </body>
</html>

请帮帮我，详细说说！

Answer 1

你显然犯了一个错误。在文档 (http://php.net/manual/en/features.file-upload.errors.php) 中，您会发现：

UPLOAD_ERR_INI_SIZE

并且您确实在脚本中指定了：

UPLOAD_ERR_INT_SIZE

这就是脚本告诉您此常量不存在的原因:)

注意：Undefined index: $error in C:\wamp\www\btb_sandbox\upload_2.php on line 35

Notice: Undefined index: $error in C:\wamp\www\btb_sandbox\upload_2.php on line 35

php

constants

syntax-error