一.找元素
①getElementById()根据ID找。
②getElementsByClassName()根据class找，返回数组。
③getElementsByTagName()根据标签名找，返回数组。
二.操作内容
1.普通元素。包括①innerText获取内容文本。②innerHTML获取内容代码。
2.表单元素。value
var a = document.getElementById("txt");
alert(a.value);
a.value = "ok";
三.操作属性
①setAttribute(属性名,属性值)设置属性
a.setAttribute("checked","checked");
②removeAttribute(属性名)移除属性
a.removeAttribute("checked");
③getAttribute(属性名)获取属性
alert(a.getAttribute("test"));
四.操作样式
a.style.width获取样式
操作样式
var a = document.getElementById("d");
1.获取样式,只能获取内嵌的
alert(a.style.width);
2.设置样式
a.style.fontSize = "30px";
3.修改样式
a.style.backgroundColor = "green";
a.style.color="white";
1.单选按钮确定提交是否可用
<body>
<div style="500px; height:500px;">
<div style="margin-top:20px;">
<input type="radio" name="sure" id="s1" onclick="KeYong()" />同意
<input type="radio" name="sure" id="s2" onclick="BuKeYong()" />不同意
</div>
<div style="margin-top:30px">
<input type="submit" value="确定" id="btn" style="100px; height:35px;" disabled="disabled" />
</div>
</div>
</body>
<script type="text/javascript">
function KeYong()
{
//找到按钮
var a = document.getElementById("btn");
//操作按钮属性
a.removeAttribute("disabled");
}
function BuKeYong()
{
var a = document.getElementById("btn");
a.setAttribute("disabled","disabled");
}
</script>
2.倒计时按钮可用
<body>
<div style="500px; height:500px; margin:100px 0px 0px 100px">
<input id="btn" type="submit" value="确定" style="100px; height:35px" disabled="disabled" />
<span id="daojishi">10</span>
<div style="margin-top:20px">
<span id="h"></span>
<span id="m"></span>
<span id="s"></span>
</div>
</div>
</body>
<script type="text/javascript">
window.setTimeout("YanChi()",1000);
function YanChi()
{
var span = document.getElementById("daojishi");
//改变span里面的值
span.innerText = span.innerText-1;
//判断是否减到了0
if(span.innerText == 0)
{
document.getElementById("btn").removeAttribute("disabled");
return;
}
window.setTimeout("YanChi()",1000);
}
window.setInterval("Bian()",1000);
function Bian()
{
var sj = new Date();
document.getElementById("h").innerText = sj.getHours();
document.getElementById("m").innerText = sj.getMinutes();
document.getElementById("s").innerText = sj.getSeconds();
}
</script>
3.向列表内添加数据
<body>
<select id="sel" style="200px;" size="10">
<option>11</option>
<option>22</option>
<option>33</option>
</select>
<input type="text" id="nr" />
<input type="button" value="添加" id="btn1" onclick="Add()" />
</body>
<script type="text/javascript">
function Add()
{
//取出用户输入的值
var v = document.getElementById("nr").value;
//向列表里面添加
var list = document.getElementById("sel");
list.innerHTML += "<option>"+v+"</option>";
alert(document.getElementById("sel").value);
}
</script>
4.两个列表之间移动数据
<body>
<div style="600px; height:500px; margin-top:20px">
<div style="200px; height:300px; float:left">
<select id="list1" size="10" style="200px; height:300px">
<option>山东</option>
<option>北京</option>
<option>河北</option>
<option>黑龙江</option>
<option>河南</option>
</select>
</div>
<div style="80px; height:300px; float:left">
<input type="button" value="单移" id="btn1" style="70px; height:30px" onclick="Dan()"/>
<input type="button" value="全移" id="btn2" style="70px; height:30px" onclick="Duo()"/>
</div>
<div style="200px; height:300px; float:left">
<select id="list2" size="10" style="200px; height:300px">
</select>
</div>
</div>
去重
<script type="text/javascript">
function Dan()
{
//把列表1选中值取出
var list1 = document.getElementById("list1");
var v = list1.value;
//造一个option项
var s = "<option class='o2'>"+v+"</option>";
//判断list2里面是否有该项
var attr = document.getElementsByClassName("o2");
var cz = true;
for(var i=0;i<attr.length;i++)
{
//alert(attr[i].innerHTML);
if(attr[i].innerHTML==v)
{
cz = false;
break;
}
}
if(cz)
{
//将option项扔到list2
var list2 = document.getElementById("list2");
list2.innerHTML +=s;
}
}
function Duo()
{
document.getElementById("list2").innerHTML = document.getElementById("list1").innerHTML;
}
</script>
5.日期时间选择
<body>
<div style="600px; height:100px;">
<select id="year">
</select>
年
<select id="month" onchange="FillDay()">
</select>
月
<select id="day">
</select>
日
</div>
</body>
<script type="text/javascript">
FillYear();
FillMonth();
FillDay();
function FillYear()
{
var sj = new Date();
var nian = sj.getFullYear();
var s = "";
for(var i=nian-5;i<nian+6;i++)
{
if(i==nian)
{
s +="<option selected='selected'>"+i+"</option>";
}
else
{
s +="<option>"+i+"</option>";
}
}
document.getElementById("year").innerHTML = s;
}
function FillMonth()
{
var sj = new Date();
var yue = sj.getMonth()+1;
var s = "";
for(var i=1;i<13;i++)
{
if(i==yue)
{
s +="<option selected='selected'>"+i+"</option>";
}
else
{
s +="<option>"+i+"</option>";
}
}
document.getElementById("month").innerHTML=s;
}
function FillDay()
{
var sj = new Date();
var tian = sj.getDate();
//取月份求天数
var yue = document.getElementById("month").value;
var n = 31;
if(yue==4 || yue==6 ||yue==9 ||yue==11)
{
n = 30;
}
else if(yue==2)
{
n=28;
}
//用循环添加
var s = "";
for(var i=1;i<n+1;i++)
{
if(i==tian)
{
s +="<option selected='selected'>"+i+"</option>";
}
else
{
s +="<option>"+i+"</option>";
}
}
document.getElementById("day").innerHTML = s;
}
function Dan()
{
//把列表1选中值取出
var list1 = document.getElementById("list1");
var v = list1.value;
//造一个option项
var s = "<option class='o2'>"+v+"</option>";
//判断list2里面是否有该项
var attr = document.getElementsByClassName("o2");
var cz = true;
for(var i=0;i<attr.length;i++)
{
//alert(attr[i].innerHTML);
if(attr[i].innerHTML==v)
{
cz = false;
break;
}
}
if(cz)
{
//将option项扔到list2
var list2 = document.getElementById("list2");
list2.innerHTML +=s;
}
}
</script>