utf-8 字符串转为Unicode编码格式

function to_unicode($string) {

$str = mb_convert_encoding($string, 'UCS-2', 'UTF-8');

$arrstr = str_split($str, 2);

$unistr = '';

foreach ($arrstr as $n) {

$dec = hexdec(bin2hex($n));

$unistr .= '&#' . $dec . ';';

}

return $unistr;

}