编辑页面
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div> </div>
<asp:DropDownList ID="DropDownList1" runat="server" Width="100px" AutoPostBack="True" Height="50px" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged" style="margin-bottom: 0px" >
</asp:DropDownList>
<asp:DropDownList ID="DropDownList2" runat="server" Width="100px" AutoPostBack="True" Height="50px" OnSelectedIndexChanged="DropDownList2_SelectedIndexChanged">
</asp:DropDownList>
<asp:DropDownList ID="DropDownList3" runat="server" Width="100px" AutoPostBack="True" Height="50px">
</asp:DropDownList>
</form>
</body>
</html>
编辑cs
public partial class Test2 : System.Web.UI.Page
{
public DataClassesDataContext context; protected void Page_Load(object sender, EventArgs e)
{
context = new DataClassesDataContext();
if(!IsPostBack)
{
databind("");
datashibind("");
dataxianbind("");
} }
private void databind(string parentareacode)
{ var querydata = from q in context.ChinaStates
where q.ParentAreaCode == parentareacode
select q;
DropDownList1.DataSource = querydata;//指定数据源 //DropDownList1.Items.Insert(0,new ListItem("请选择单位")); DropDownList1.DataTextField = "AreaName";//界面上显示的是地名
DropDownList1.DataValueField = "AreaCode";//存的是地区编号 DropDownList1.DataBind(); }
private void datashibind(string parentareacode)
{
var querydata = from q in context.ChinaStates
where q.ParentAreaCode ==parentareacode
select q;
DropDownList2.DataSource = querydata; DropDownList2.DataTextField = "AreaName";//界面上显示的是地名
DropDownList2.DataValueField = "AreaCode";//存的是地区编号
DropDownList2.DataBind(); }
private void dataxianbind(string parentareacode)
{ var querydata = context.ChinaStates.Where(r=>r.ParentAreaCode==parentareacode);
DropDownList3.DataSource = querydata;
DropDownList3.DataTextField = "AreaName";//界面上显示的是地名
DropDownList3.DataValueField = "AreaCode";//存的是地区编号
DropDownList3.DataBind(); }
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
string code = DropDownList1.SelectedValue.ToString();
datashibind(code);
if (DropDownList2.Items.Count > )
{
string s = DropDownList2.SelectedItem.Value.ToString();
dataxianbind(s);
}
else
{
DropDownList3.Items.Clear();
} }
protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
{
string code = DropDownList2.SelectedValue.ToString();
dataxianbind(code); }
}