jsp 页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="java.util.Date" %>
<%@page import="java.text.SimpleDateFormat" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<% //java 代码
Date d= new Date();
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String str = df.format(d);
%>
<%=str %> //显示出来
<select size=1>
<option value="1" >one</option>
<option value="2" >two</option>
<option value="3" selected>three</option> //selected 表示此项被选为默认
<option value="4" >four</option>
</select>
<%-- <jsp:forward page="wrong.jsp"/> --%> //请求转发
</body>
</html>
select 的小技巧
1.动态创建select
function createSelect(){
var mySelect = document.createElement("select");
mySelect.id = "mySelect";
document.body.appendChild(mySelect);
}
2.添加选项option
function addOption(){
//根据id查找对象，
var obj=document.getElementById('mySelect');
//添加一个选项
obj.add(new Option("文本","值"));
}
3.删除所有选项option
function removeAll(){
var obj=document.getElementById('mySelect');
obj.options.length=0;
}
4.删除一个选项option
function removeOne(){
var obj=document.getElementById('mySelect');
//index,要删除选项的序号，这里取当前选中选项的序号
var index=obj.selectedIndex;
obj.options.remove(index);
}
5.获得选项option的值
var obj=document.getElementById('mySelect');
var index=obj.selectedIndex; //序号，取当前选中选项的序号
var val = obj.options[index].value;
6.获得选项option的文本
var obj=document.getElementById('mySelect');
var index=obj.selectedIndex; //序号，取当前选中选项的序号
var val = obj.options[index].text;
7.修改选项option
var obj=document.getElementById('mySelect');
var index=obj.selectedIndex; //序号，取当前选中选项的序号
var val = obj.options[index]=new Option("新文本","新值");
8.删除select
function removeSelect(){
var mySelect = document.getElementById("mySelect");
mySelect.parentNode.removeChild(mySelect);
}
9.设置select optin被中