文件上传条件

Question

我有一个 html 表单，其中包含一些提交到 PHP 页面的文本和文件输入。我想错误检查图像文件输入，但前提是他们选择包含一个。有没有办法检查是否有上传的图像文件？我在下面包含了我的尝试，但它似乎没有用。

if ($_FILES['image'])
{ 
    if ($_FILES['image']['error'] > 0)
    {
        echo 'Problem: '; }}
        switch ($_FILES['image']['error'])
        {
            case 1: echo 'File exceeded upload_max_filesize.';
                break;
            case 2: echo 'File exceeded max_file_size.';
                break:
            case 3: echo 'File only partially uploaded.';
                break;
            case 4: echo 'No file uploaded.';
                break;
            default: echo 'cannot upload.';
                break;
        } 
        exit;
    }
}

Answer 1

来自PHP manual

If no file is selected for upload in your form, PHP will return $_FILES['userfile']['size'] as 0, and $_FILES['userfile']['tmp_name'] as none.

即：测试 $_FILES 元素将始终 return 为真。您应该改为测试文件大小和临时名称元素。

文件上传条件

File Upload Conditional

php

if-statement

file-upload