Change GridView Row Cell Color When Text Match From Textbox

Points

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Demo.aspx.cs" Inherits="architecture.Demo" %>
<!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>
</head>
<body>
<form id="form1" runat="server">
<div> <label>Enter First Name</label>
<asp:TextBox ID="txtColor" runat="server"></asp:TextBox>
<asp:Button ID="btnAdd" runat="server" Text="Submit" OnClick="Submit" /> <br />
<asp:GridView ID="gvlist" runat="server" AutoGenerateColumns="false" OnRowDataBound="GridView1_RowDataBound" CellPadding="4" ForeColor="#333333">
<Columns>
<asp:BoundField DataField="FirstName" HeaderText="FirstName" />
<asp:BoundField DataField="LastName" HeaderText="FirstName" /> </Columns>
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<RowStyle BackColor="#F7F6F3" ForeColor="#333333" /> </asp:GridView>
</div>
</form>
</body>
</html>

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.Configuration;
using System.Data.SqlClient;
using System.IO;
namespace architecture
{
public partial class Demo: System.Web.UI.Page
{
SqlConnection con;
DataTable dt;
//Connection String from Web.config file
public static string constr = ConfigurationManager.ConnectionStrings["ConString"].ConnectionString;
protected void Page_Load(object sender, EventArgs e)
{
lblTime.Text = DateTime.Today.DayOfWeek.ToString();
if (!IsPostBack)
{
ShowData();
}
}
//method for Displaying Data in Gridview
protected void ShowData()
{
SqlConnection con = new SqlConnection(constr);
string str = "Select * from TbDemo; select * from TbDemo";
con.Open();
SqlCommand cmd = new SqlCommand(str, con);
DataTable dt = new DataTable();
SqlDataReader reader = cmd.ExecuteReader();
dt.Load(reader);
DataView dv = dt.DefaultView;
gvlist.DataSource = dv;
gvlist.DataBind();
int i = 0;
foreach(DataRow dr in dt.Rows)
{
if (i == 3)
{
Response.Write(dr["FirstName"] + "</br>");
}
i++;
}
con.Close();
}
//RowDataBound Event
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
//Checking the RowType of the Row
if (txtColor.Text.Trim() != "")
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
if (e.Row.Cells[0].Text == txtColor.Text) {
e.Row.Cells[0].ForeColor = System.Drawing.Color.Red;;
}
}
}
}
protected void Submit(object sender, EventArgs e) {
ShowData();
}
}
}