1.方法一：

2.方法2：

//生成16位的串 $randLength=6;$chars='abcdefghijklmnopqrstuvwxyz';$len=strlen($chars);$randStr='';for ($i=0;$i<$randLength;$i++){   $randStr.=$chars[rand(0,$len-1)];}$tokenvalue=$randStr.time();

 3.方法3:

$str = str_shuffle('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890');$str = $str.uniqid();return md5($str);