<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>
<script type="text/javascript">
$(function () {
$(".cg2").change(function () {
var id = $(this).attr("id");
var value = $(this).val();
var newid = '#'+id.replace('_1_', '_2_');// The first 1 column id Replace the first 2 column id
//alert(newid);
var data = "t1*v1|t2*v2|t3*v3";// The format of the data that we're getting in the background, we're using fixed values here
var datas = data.split('|');// Divide into groups
for (var i = 0; i < datas.length; i++) {
var d1 = datas[i].split('*');// Divide each group into two parts Displays values and true values
$(newid).append("<option value=\""+d1[1]+"\">" + d1[0] + "</option>");
//alert(d1);
}
// alert(id + "|||" + value);
});
})
</script>
</head>
<body>
<form id="form1" runat="server">
<div> In order to satisfy two columns, any number of rows. Background dynamic generation of drop-down box, but also before and after the cascading requirements. use js+jquery , using a server control +Ajax No, not always after the choice
<asp:DropDownList ID="ddl_1_1" CssClass="cg2" runat="server">
<asp:ListItem Text="txt1" Value="val1"></asp:ListItem>
<asp:ListItem Text="txt1" Value="val1"></asp:ListItem>
<asp:ListItem Text="txt1" Value="val1"></asp:ListItem>
</asp:DropDownList>
<asp:DropDownList ID="ddl_2_1" runat="server">
</asp:DropDownList><br/>
<asp:DropDownList ID="ddl_1_2" CssClass="cg2" runat="server">
<asp:ListItem Text="txt2" Value="val2"></asp:ListItem>
<asp:ListItem Text="txt2" Value="val2"></asp:ListItem>
<asp:ListItem Text="txt2" Value="val2"></asp:ListItem>
</asp:DropDownList>
<asp:DropDownList ID="ddl_2_2" runat="server">
</asp:DropDownList><br/>
<asp:Button ID="ButtonGet" runat="server" Text=" To obtain " onclick="ButtonGet_Click" />
<asp:Label ID="Label1" runat="server" Text=""></asp:Label>
</div>
</form>
</body>
</html>
// The background
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
}
}
protected void ButtonGet_Click(object sender, EventArgs e)
{
/// To get through js And choose ddl_2_1 Control displays the selected value in Label1 On.
Label1.Text = Request["ddl_2_1"].ToString();
}