它就来了（假设使用UTF-8，但是更改起来很简单）：
function enpre($str) { $str = mb_convert_encoding($str , 'UTF-32', 'UTF-8'); //big endian $split = str_split($str, 4); $res = ""; foreach ($split as $c) { $cur = 0; for ($i = 0; $i < 4; $i++) { $cur |= ord($c[$i]) << (8*(3 - $i)); } $res .= "&#" . $cur . ";"; } return $res;}编辑 推荐的替代使用
unpack：
function enpre2($str) { $str = mb_convert_encoding($str , 'UTF-32', 'UTF-8'); $t = unpack("N*", $str); $t = array_map(function($n) { return "&#$n;"; }, $t); return implode("", $t);}
