Introduction

In this example we will export Grid view data populated by Database to CSV File.

This is the html source of the page

<%@ Page Language="C#" AutoEventWireup="true" EnableEventValidation="false" CodeFile="Register.aspx.cs" Inherits="Register" %>
<!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>
 <asp:GridView ID="grdDetail" Width="400px" runat="server"
AutoGenerateColumns="False" AllowPaging="true" PageSize="5"
BackColor="White" BorderColor="White" BorderStyle="Ridge"
BorderWidth="2px" CellPadding="3" CellSpacing="1" DataKeyNames="Id"
 GridLines="None" AllowSorting="true" >
 <RowStyle BackColor="#DEDFDE" ForeColor="Black" />
 <Columns>
<asp:BoundField DataField="Name" HeaderText="Name" />
 <asp:BoundField DataField="EmpId" HeaderText="EmpId" />
 <asp:BoundField DataField="ContactNo" HeaderText="ContactNo" />
 <asp:BoundField DataField="EmailId" HeaderText="EmailId" />
 <asp:BoundField DataField="Address" HeaderText="Address" />
 </Columns>
 <FooterStyle BackColor="#C6C3C6" ForeColor="Black" />
 <PagerStyle BackColor="#C6C3C6" ForeColor="Black" HorizontalAlign="Right" />
 <SelectedRowStyle BackColor="#9471DE" Font-Bold="True" ForeColor="White" />
 <HeaderStyle BackColor="#4A3C8C" Font-Bold="True" ForeColor="#E7E7FF" />
 </asp:GridView>
 <asp:Button ID="Export" runat="server" Text="Export To CSV" onclick="Export_Click" />
 </div>
 </form>
 </body>
</html>

The complete code of Register.aspx.cs Page in Code Behind:

 using System;
 using System.Web;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web.Security;
 using System.Web.UI;
 using System.Web.UI.WebControls;
 using System.Web.UI.Adapters;
 using System.Web.UI.WebControls.WebParts;
 using System.Web.UI.HtmlControls;
 using System.Data.SqlClient;
 using System.Data;
 using System.Text;
 using System.IO;
 using iTextSharp.text;
 using iTextSharp.text.pdf;
 using iTextSharp.text.html.simpleparser;

 public partial class Register : System.Web.UI.Page
 {
DataTable dtCsv = new DataTable();
BAL objBAL = new BAL();
 protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
fillgrid();
}
}
 public void fillgrid()
{
DataSet ds = new DataSet();
ds = objBAL.Fill_Grid();//Function defined in BAL Class
 dtCsv = ds.Tables[0];
grdDetail.DataSource = ds.Tables[0];
grdDetail.DataBind();

 }
protected void btnExport_Click(object sender, EventArgs e)
{
 fillgrid();
CreateCSVFile(dtCsv, "c:\\" + "Register" + ".csv" + "");
}

public void CreateCSVFile(DataTable dt, string strFilePath)
{
StreamWriter sw = new StreamWriter(strFilePath, false);
int iColCount = dt.Columns.Count;
for (int i = 0; i < iColCount; i++)
{
sw.Write(dt.Columns[i]);
if (i < iColCount - 1)
{
sw.Write(",");
}
}
sw.Write(sw.NewLine);
// Now write all the rows.
 foreach (DataRow dr in dt.Rows)
{
for (int i = 0; i < iColCount; i++)
{
if (!Convert.IsDBNull(dr[i]))
{
sw.Write(dr[i].ToString());
}
if (i < iColCount - 1)
{
sw.Write(",");
}
}
sw.Write(sw.NewLine);
}
sw.Close();
}

 public override void VerifyRenderingInServerForm(Control control)
{
 }
}

App_Code BAL.cs

using System;
 using System.Web;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web.Security;
 using System.Web.UI;
 using System.Web.UI.WebControls;
 using System.Web.UI.Adapters;
 using System.Web.UI.WebControls.WebParts;
 using System.Web.UI.HtmlControls;
 using System.Data.SqlClient;
 using System.Data;
 public class BAL
{
public BAL()
{
//
 // TODO: Add constructor logic here
 //
 }

 #region "variable"
#region "Properties"
 #region "Functions"
 public DataSet Fill_Grid()
{
 SqlConnection conn = new SqlConnection(connectionString);
 SqlCommand cmd = new SqlCommand("SELECT * from Register", conn);
cmd.CommandType = CommandType.Text;
SqlDataAdapter adap = new SqlDataAdapter(cmd);
 DataSet ds = new DataSet();
adap.Fill(ds);
 return ds;
 }
 #endregion
 }