php 随机生成字符串
private function createNonceStr($length = 16) { $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; $str = ""; for ($i = 0; $i < $length; $i++) { $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1); } return $str; }