<!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> <style type="text/css"> ul { list-style:none; } </style> <script type="text/javascript"> window.onload = function() { var obj = document.getElementById('demo').getElementsByTagName('input'); for (var i = 0; i < obj.length; i ++) { obj[i].onclick = function() { //查找并选择/取消选择所有子项 var childrenObj = this.parentNode.getElementsByTagName('ul'); if (childrenObj.length > 0) { for (var j = 0; j < childrenObj.length; j ++) { var o = childrenObj[j].getElementsByTagName('input'); for (var k = 0; k < o.length; k ++) o[k].checked = this.checked; } } //递归方法检查并设置父选项选择状态 checkParent(this); } } } function checkParent(obj) { var parentObj = obj.parentNode.parentNode; if (parentObj.id != 'demo') { parentObj = parentObj.parentNode; var FLAG = true; //标志位，true表示父级选项的所有子选项都是选中的，初始值为true，假设全部为选中 var o = parentObj.getElementsByTagName('input'); for (var i = 1; i < o.length; i ++) { if (!o[i].checked) { FLAG = false; break; } } if (FLAG) o[0].checked = true; else o[0].checked = false; if (parentObj.parentNode.parentNode.id != 'demo') checkParent(o[0]); } } </script> </head> <body> <form id="weaver" name="frmmain" method="post"> <ul id="demo"> <li><input type="checkbox" />系统使用 <ul> <li><input type="checkbox" />系统使用规范</li> <li><input type="checkbox" />系统功能介绍 <ul> <li><input type="checkbox" />三级选项1 <ul> <li><input type="checkbox" />四级选项1</li> </ul> </li> <li><input type="checkbox" />三级选项2</li> </ul> </li> </ul> </li> <li><input type="checkbox" />会议资料 <ul> <li><input type="checkbox" />会议资料</li> </ul> </li> </ul> </form> </body> </html>