??  ????????????2??

??????1????????????????????м?????????????????????????????????????????

??????2???????￡??????????棩????????????????????????????????

??????2????μ??????

????1??????CTRL + F5

????2??????CTRL + ???????????°??

????3??????CTRL + ?????????????°??

??????1????μ??????

????1?????????????°??

????2???????????????°??

????3????????????????????°??

????4?????????->????????

????5??????F5

????6??????SHIFT + F5

????7???????????????

????8??????CTRL + ??????????????????°??

????9??????CTRL + ???????->????????

????10??Webkit???￡?????CTRL + R

???????????????????????????????β??????????????????????????????????

????REFRESH_NORMAL

????Refresh without sending a ??Pragma:no-cache?? HTTP header to the server.REFRESH_IFEXPIRED

????Not currently implemented.REFRESH_COMPLETELY

????Refresh without forced cache validation by sending a ??Pragma:no-cache?? header to the server ??HTTP URLs only??. Same as pressing Ctrl+F5 in Microsoft Internet Explorer.

?????????????http://download.taobaocdn.com/client/browser/download.php

???????????в???wireshark???в?????????????????????wireshark????????????????http????е?????????? [Hypertext Transfer Protocol]?а???? [Cache-control:no-cache]??????￡???????[Cache-control:no-cache]??????????

???????? http1.0???pragma: no-cache????  http1.1???? ??Cache-Control: no-cache?????????????о????￡?

?????????????http 1.1???????  ????pragma??no-cache  ???Cache-Control: no-cache

????????????? http 1.0??????? ???pragma??no-cache

?????????????????????http 1.1?  ???????.