First we need to create 3 Tables in SQL Server Database.
1) Country Table :
2) State Table :
3) Region Table :
Now fill data in the tables as follows :-
1) Country Table :
2) State Table :
3) Region Table :
Your Default.aspx page :-
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!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></title>
<style type="text/css">
.style1
{
width: 93px;
}
.style2
{
width: 93px;
height: 26px;
}
.style3
{
height: 26px;
width: 96px;
}
.style4
{
width: 96px;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<table align="center">
<tr>
<td>
Country:
</td>
<td>
<asp:DropDownList ID="ddlCountry" runat="server" AutoPostBack="true"
onselectedindexchanged="ddlCountry_SelectedIndexChanged"></asp:DropDownList>
</td>
</tr>
<tr>
<td>
State:
</td>
<td>
<asp:DropDownList ID="ddlState" runat="server" AutoPostBack="true"
onselectedindexchanged="ddlState_SelectedIndexChanged"></asp:DropDownList>
</td>
</tr>
<tr>
<td>
Region:
</td>
<td>
<asp:DropDownList ID="ddlRegion" runat="server"></asp:DropDownList>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
Your Default.aspx.cs Page :-
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
public partial class _Default : System.Web.UI.Page
{
SqlConnection cn;
protected void Page_Load(object sender, EventArgs e)
{
cn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=E:\C#\WebSites\DropDownList DataBase 2\App_Data\Database.mdf;Integrated Security=True;User Instance=True");
if (!IsPostBack)
{
BindContrydropdown();
}
}
protected void BindContrydropdown()
{
//conenction path for database
cn.Open();
SqlCommand cmd = new SqlCommand("select * from Country", cn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
cn.Close();
ddlCountry.DataSource = ds;
ddlCountry.DataTextField = "Cname";
ddlCountry.DataValueField = "Cid";
ddlCountry.DataBind();
ddlCountry.Items.Insert(0, new ListItem("--Select--", "0"));
ddlState.Items.Insert(0, new ListItem("--Select--", "0"));
ddlRegion.Items.Insert(0, new ListItem("--Select--", "0"));
}
protected void ddlCountry_SelectedIndexChanged(object sender, EventArgs e)
{
int CountryID = Convert.ToInt32(ddlCountry.SelectedValue);
cn.Open();
SqlCommand cmd = new SqlCommand("select * from State where Cid=" + CountryID, cn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
cn.Close();
ddlState.DataSource = ds;
ddlState.DataTextField = "Sname";
ddlState.DataValueField = "Sid";
ddlState.DataBind();
ddlState.Items.Insert(0, new ListItem("--Select--", "0"));
if (ddlState.SelectedValue == "0")
{
ddlRegion.Items.Clear();
ddlRegion.Items.Insert(0, new ListItem("--Select--", "0"));
}
}
protected void ddlState_SelectedIndexChanged(object sender, EventArgs e)
protected void ddlState_SelectedIndexChanged(object sender, EventArgs e)
{
int StateID = Convert.ToInt32(ddlState.SelectedValue);
cn.Open();
SqlCommand cmd = new SqlCommand("select * from Region where Sid=" + StateID, cn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
cn.Close();
ddlRegion.DataSource = ds;
ddlRegion.DataTextField = "Name";
ddlRegion.DataValueField = "Rid";
ddlRegion.DataBind();
ddlRegion.Items.Insert(0, new ListItem("--Select--", "0"));
}
}
Output:-
No comments:
Post a Comment