<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>jQuery 全选 全不选</title>
<script src="Scripts/jquery-1.4.4.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(function () {
$("#chkAll").click(function () {
$("input[name='chk']").attr("checked", $(this).attr("checked")); //注意
});
$("input[name='chk']").each(function () {
$(this).click(function () {
if ($("input[name='chk']:checked").length == $("input[name='chk']").length) {
$("#chkAll").attr("checked", true) //当元素全部选择后，控制全部的checkbox也处于选定状态
} else {
$("#chkAll").attr("checked", false); //只要有一个没有选择控制全选的checkbox是不会checked的
}
})
});
});
</script>
</head>
<body>
<input type="checkbox" id="checkbox1" name="chk" ><label for="checkbox1">aaaaaa</label><br>
<input type="checkbox" id="checkbox2" name="chk" ><label for="checkbox2">bbbbbb</label><br>
<input type="checkbox" id="checkbox3" name="chk" ><label for="checkbox3">cccccc</label><br>
<input type="checkbox" id="checkbox4" name="chk" ><label for="checkbox4">dddddd</label><br>
<input type="checkbox" id="checkbox5" name="chk" ><label for="checkbox5">eeeeee</label><br><br>
<input type="checkbox" id="chkAll" name="chkAll" /><label for="chkAll">全选</label>
</body>
</html>