获取毫秒级时间戳

//获取毫秒级时间戳
   public function GetMicrotime($value='')
   {
       //  获取毫秒的时间戳  
       $time = explode ( " ", microtime () );  
       $time = $time [1] . ($time [0] * 1000);  
       $time2 = explode ( ".", $time );  
       $time = $time2 [0];
       // dump($time);
       // dump(time());
       return $time;
   }