res.attachment([filename])

将 HTTP 响应 Content-Disposition 标头字段设置为 "attachment"。如果给出了 filename，那么它会根据扩展名通过 res.type() 设置 Content-Type，并设置 Content-Disposition "filename=" 参数。

Sets the HTTP response Content-Disposition header field to "attachment". If a filename is given, then it sets the Content-Type based on the extension name via res.type(), and sets the Content-Disposition "filename=" parameter.

res.attachment()
// Content-Disposition: attachment

res.attachment('path/to/logo.png')
// Content-Disposition: attachment; filename="logo.png"
// Content-Type: image/png