Question

基本问题是：我有一个图像文件的链接。单击链接时所需的行为是获取下载对话框，这将允许我启动相关的图像编辑器。这不会发生，因为图像文件是由浏览器呈现的。

当用户点击链接时，是否有任何html魔法可用于强制浏览器提供下载对话框？

非常感谢任何帮助或指示。

Answer 1

两种方法：

在锚标记的href中使用Data URIs：

<a href="data:image/png;base64,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">Download</a>
在某些特定的浏览器中，例如Google Chrome和Firefox，您可以这样做：

<a download="image.jpg" href="http://www.domain.com/image.jpg">Download</a>

Answer 2

仅使用HTML是不可能的，但您可以通过使用服务器端语言（如PHP）修改标题来强制下载文件。


// grab the requested file's name
$file_name = $_GET['file'];

// make sure it's a file before doing anything!
if(is_file($file_name))
{

    /*
        Do any processing you'd like here:
        1.  Increment a counter
        2.  Do something with the DB
        3.  Check user permissions
        4.  Anything you want!
    */

    // required for IE
    if(ini_get('zlib.output_compression')) { ini_set('zlib.output_compression', 'Off'); }

    // get the file mime type using the file extension
    switch(strtolower(substr(strrchr($file_name,'.'),1)))
    {
        case 'pdf': $mime = 'application/pdf'; break;
        case 'zip': $mime = 'application/zip'; break;
        case 'jpeg':
        case 'jpg': $mime = 'image/jpg'; break;
        default: $mime = 'application/force-download';
    }
    header('Pragma: public');   // required
    header('Expires: 0');       // no cache
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header('Last-Modified: '.gmdate ('D, d M Y H:i:s', filemtime ($file_name)).' GMT');
    header('Cache-Control: private',false);
    header('Content-Type: '.$mime);
    header('Content-Disposition: attachment; filename="'.basename($file_name).'"');
    header('Content-Transfer-Encoding: binary');
    header('Content-Length: '.filesize($file_name));    // provide file size
    header('Connection: close');
    readfile($file_name);       // push it out
    exit();

}

Answer 3

如果要显示下载对话框，则需要为图像添加特殊标题

PHP中的

将是：

header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename=image.jpg');
header('Content-Transfer-Encoding: binary');

Answer 4

另一种解决方案是将其添加到包含图像的文件夹中的htaccess文件中：

AddType application/octet-stream .jpg

html下载标签

4 个答案: