public function newName($name){
//获取文件后缀名
$extension = substr($name,strrpos($name,"."));
//当前时间转化为毫秒----microtime
$md5 = md5(microtime().rand(10000,1000000));
$fileName="./Upload/".substr($md5,0,8).'-'.substr($md5,8,4).'-'.substr($md5,12,4).'-'.substr($md5,16,8).'-'.substr($md5,16,8).strtolower($extension);
return $fileName;
}