JavaScript操作DropDownList的通用方法，来自ASP.NET Forum, NC01
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ddl.aspx.cs" Inherits="ddl" %>
<!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 runat="server">
<title>Untitled Page</title>
<script type="text/javascript">
<!--
function setDropDownList(elementRef, valueToSetTo)
{
var isFound = false;
for (var i=0; i<elementRef.options.length; i++)
{
if ( elementRef.options[i].value == valueToSetTo )
{
elementRef.options[i].selected = true;
isFound = true;
}
}
if ( isFound == false )
elementRef.options[0].selected = true;
}
function setDatosCGA(ddl,strEstadoCarta)
{
setDropDownList(document.getElementById(ddl), strEstadoCarta);
}
function Button1_onclick() {
setDatosCGA('<%=DropDownList1.ClientID %>','cc');
}
// -->
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:DropDownList ID="DropDownList1" runat="server">
<asp:ListItem>aa</asp:ListItem>
<asp:ListItem>bb</asp:ListItem>
<asp:ListItem>cc</asp:ListItem>
<asp:ListItem>dd</asp:ListItem>
<asp:ListItem>ee</asp:ListItem>
</asp:DropDownList>
<input id="Button1" type="button" value="button" onclick="return Button1_onclick()" />
</div>
</form>
</body>
</html>
<!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 runat="server">
<title>Untitled Page</title>
<script type="text/javascript">
<!--
function setDropDownList(elementRef, valueToSetTo)
{
var isFound = false;
for (var i=0; i<elementRef.options.length; i++)
{
if ( elementRef.options[i].value == valueToSetTo )
{
elementRef.options[i].selected = true;
isFound = true;
}
}
if ( isFound == false )
elementRef.options[0].selected = true;
}
function setDatosCGA(ddl,strEstadoCarta)
{
setDropDownList(document.getElementById(ddl), strEstadoCarta);
}
function Button1_onclick() {
setDatosCGA('<%=DropDownList1.ClientID %>','cc');
}
// -->
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:DropDownList ID="DropDownList1" runat="server">
<asp:ListItem>aa</asp:ListItem>
<asp:ListItem>bb</asp:ListItem>
<asp:ListItem>cc</asp:ListItem>
<asp:ListItem>dd</asp:ListItem>
<asp:ListItem>ee</asp:ListItem>
</asp:DropDownList>
<input id="Button1" type="button" value="button" onclick="return Button1_onclick()" />
</div>
</form>
</body>
</html>