SegmentFault, 知乎, 点点的的scroll to top功能有现成的插件吗? 解决方案 有很多,比如:http://briancray.com/2009/10/06/scrol...http://davidwalsh.name/jquery-top-lin...http://www.dynamicdrive.com/dynamicin...http://lab.mattvarone.com/projects/jq...