有趣。我会警惕地将其视为解决垃圾邮件/替换capcha的解决方案，但这确实使垃圾邮件发送者的生活更加困难。

Interesting. I'd be wary of thinking of it as a solution to spam / replacement for capcha, but it does make the spammers life more difficult.

但是您应该计划如何处理在禁用了javascript的情况下（可能还有CSS）-例如通过为表单分配一个div，但保留默认消息，然后使用javascript将表单写入表单（内联而不是等待onload / pageready）。

However you should plan for dealing with cases where javascript is disabled (and potentially CSS too) - e.g. by assigning a div for the form, but leaving it with a default message, then writing the form into it using javascript (inline rather than waiting for onload/pageready).

$ string = md5（$ _ SERVER ['REMOTE_ADDR']）

$string = md5($_SERVER['REMOTE_ADDR'])

这不是随机值-它不会改变。考虑：

This is not a random value - and it won't change. Consider:

$ string = sha1（$ _ SERVER ['REMOTE_ADDR']。rand（1000）.time（））;

$string = sha1($_SERVER['REMOTE_ADDR'].rand(1000).time());

（尽管底层算法需要更多操作，sha1还是比md5快）。

(sha1 is slightly faster than md5 despite the underlying algorithm requiring more ops).

使用会话可能是一个好主意，并且：

It might be a good idea to use a session, and:

$ _ SERVER ['string'] = sha1（session_id（）。 rand（1000）.time（））;

$_SERVER['string'] = sha1(session_id().rand(1000).time());