练习-checkbox 全选 ，反选， 单选，以及取值
1.方法1
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>全选与反选</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<script language=javascript>
function unselectall(){
if(document.myform.chkAll.checked){
document.myform.chkAll.checked = document.myform.chkAll.checked&0;
}
}
function CheckAll(form){
for (var i=0;i<form.elements.length;i++){
var e = form.elements[i];
if (e.Name != 'chkAll'&&e.disabled==false)
e.checked = form.chkAll.checked;
}
}
</script>
在网页中html中的代码:
<form name="myform" method="post" id="myform" action="" >
<input name='id' type='checkbox' onclick='unselectall()' id='id' value='1'> 设计家园
<input name='id' type='checkbox' onclick='unselectall()' id='id' value='2'> 网页教程
<input name='id' type='checkbox' onclick='unselectall()' id='id' value='3'> 酷站欣赏
<input name='id' type='checkbox' onclick='unselectall()' id='id' value='4'> 网页素材
<input name='chkAll' type='checkbox' id='chkAll' onclick='CheckAll(this.form)' value='checkbox'>
全选
</form>
</body>
</html>
2.方法2：
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>全选与反选</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<script language="javascript">
// --列头全选框被单击---
function ChkAllClick(sonName, cbAllId){
var arrSon = document.getElementsByName(sonName);
var cbAll = document.getElementById(cbAllId);
var tempState=cbAll.checked;
for(i=0;i<arrSon.length;i++) {
if(arrSon[i].checked!=tempState)
arrSon[i].click();
}
}
// --子项复选框被单击---
function ChkSonClick(sonName, cbAllId) {
var arrSon = document.getElementsByName(sonName);
var cbAll = document.getElementById(cbAllId);
for(var i=0; i<arrSon.length; i++) {
if(!arrSon[i].checked) {
cbAll.checked = false;
return;
}
}
cbAll.checked = true;
}
// --反选被单击---
function ChkOppClick(sonName){
var arrSon = document.getElementsByName(sonName);
for(i=0;i<arrSon.length;i++) {
arrSon[i].click();
}
}
</script>
</head>
<body>
<form name="form1" method="post" action="">
<table width="500" border="1">
<tr bgcolor="#FFFF66">
<td>
<INPUT name="chkAll" id="chkAll" title="全选" onClick="ChkAllClick('chkSon','chkAll')" type="checkbox" />全选</td>
<td align="center">复选框全选示例 </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td><INPUT name="chkSon" id="chkSon1" type="checkbox" value='1' onclick="ChkSonClick('chkSon','chkAll')" />1</td>
<td> 作用： </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td><INPUT name="chkSon" id="chkSon2" type="checkbox" value='2' onclick="ChkSonClick('chkSon','chkAll')" />2</td>
<td> a.单击列头复选框全选或全不选子项 </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td><INPUT name="chkSon" id="chkSon3" type="checkbox" value='3' onclick="ChkSonClick('chkSon','chkAll')" />3</td>
<td> b.只要有一个子项没有选中，则取消列头的选中状态 </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td><INPUT name="chkSon" id="chkSon4" type="checkbox" value='4' onclick="ChkSonClick('chkSon','chkAll')" />4</td>
<td> c.当所有子项目选中时，列头复选框自动置为选中状态 </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td><INPUT name="chkSon" id="chkSon5" type="checkbox" value='5' onclick="ChkSonClick('chkSon','chkAll')" />5</td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td><INPUT name="chkSon" id="chkSon6" type="checkbox" value='6' onclick="ChkSonClick('chkSon','chkAll')" />6</td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td><INPUT name="chkSon" id="chkSon7" type="checkbox" value='7' onclick="ChkSonClick('chkSon','chkAll')" />7</td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td><INPUT name="chkSon" id="chkSon8" type="checkbox" value='8' onclick="ChkSonClick('chkSon','chkAll')" />8</td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td><INPUT name="chkSon" id="chkSon9" type="checkbox" value='9' onclick="ChkSonClick('chkSon','chkAll')" />9</td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td><INPUT name="chkSon" id="chkSon10" type="checkbox" value='10' onclick="ChkSonClick('chkSon','chkAll')" />10</td>
<td>d.将复选框反过来选</td>
<td> </td>
<td> </td>
</tr>
<tr bgcolor="#66FFFF">
<td><INPUT name="chkOpposite" id="chkOpposite" title="反选" onClick="ChkOppClick('chkSon')" type="checkbox" />反选</td>
<td align="center">反选示例</td>
<td> </td>
<td> </td>
</tr>
</table>
</form>
</body>
</html>
3.取值
var num=0;
var value=[];
var c=document.getElementsByTagName("INPUT");
for(var i=0;i<c.length;i++){
if(c[i].type=="checkbox"&&c[i].checked)
{
num++;
value[value.length]=c[i].value;
}
}
alert("共有"+num+"个复选框被选中,值为"+value);
