In this blog we will know when selected any item from the
dropdown list all records related to this will be displayed in a grid view
without refreshing the whole webpage.
Table Creation
Create table Contacts (id varchar(50),name varchar(50),city
varchar(50))
<%@ 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>Untitled
Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="up1" runat="server">
<ContentTemplate >
<asp:Label ID="Label1" runat="server" Text="Choose Name" BackColor="#FFFF99"
ForeColor="Red" Width="100px"></asp:Label>
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True"
onselectedindexchanged="DropDownList1_SelectedIndexChanged" >
</asp:DropDownList>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID
="DropDownList1" />
</Triggers>
</asp:UpdatePanel>
<br />
<asp:UpdatePanel ID="up2" runat="server">
<ContentTemplate >
<asp:GridView ID="GridView1" runat="server">
</asp:GridView>
</ContentTemplate>
<Triggers >
<asp:AsyncPostBackTrigger ControlID
="GridView1" />
</Triggers>
</asp:UpdatePanel>
<br />
</div>
</form>
</body>
</html>
using System;
using
System.Configuration;
using
System.Data;
using
System.Linq;
using
System.Web;
using
System.Web.Security;
using
System.Web.UI;
using
System.Web.UI.HtmlControls;
using
System.Web.UI.WebControls;
using
System.Web.UI.WebControls.WebParts;
using
System.Xml.Linq;
using
System.Data.SqlClient;
public partial class _Default : System.Web.UI.Page
{
string
connStr = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
SqlDataAdapter
ad = new SqlDataAdapter();
SqlCommand
cmd = new SqlCommand();
SqlDataAdapter
sqlda;
DataSet
ds;
string str;
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs
e)
{
SqlConnection
conn = new SqlConnection(connStr);
conn.Open();
str = "select
* from Contacts where name like '" + DropDownList1.SelectedValue + "'";
cmd = new
SqlCommand(str, conn);
sqlda = new
SqlDataAdapter(cmd);
ds = new
DataSet();
sqlda.Fill(ds, "Contacts");
conn.Close();
GridView1.DataSource = ds;
GridView1.DataMember = "Contacts";
GridView1.DataBind();
}
protected void Page_Load(object
sender, EventArgs e)
{
SqlConnection
con = new SqlConnection(connStr);
if
(!IsPostBack)
{
DropDownList1.Items.Add("Choose name");
con.Open();
str = "select
name from Contacts";
cmd = new
SqlCommand(str, con);
SqlDataReader
reader = cmd.ExecuteReader();
while
(reader.Read())
{
DropDownList1.Items.Add(reader["name"].ToString());
}
reader.Close();
con.Close();
}
}
}