<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>无标题文档</title> </head> <body> <div style="overflow:hidden; margin:auto; 100px;">不设置height,加上overflow:hidden; 层就自动适应高度</div> <div style="overflow:hidden; margin:auto; 100px;">不设置height,加上overflow:hidden; 层就自动适应高度</div> </body> </html>