export gridview to excel,word,pdf and print in asp.net with c#

Default.aspx

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"
    CodeFile="Default.aspx.cs" Inherits="_Default" %>

<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">
</asp:Content>
<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
    <br />
    <center>    <asp:Button ID="btn1" runat="server" Text="Export to Excel" OnClick="btn1_Click" />
        <asp:Button ID="Button1" runat="server" Text="Export to Word"
            onclick="Button1_Click"/>
        <asp:Button ID="Button2" runat="server" Text="Export to PDF"
            onclick="Button2_Click"/>
        <input id="Submit1" onclick="window.print()" type="submit" value="Print" /><br />
    <br />
 
    <asp:GridView ID="gv1" runat="server">
    </asp:GridView>
    </center>

</asp:Content>

Default.aspx.cs

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;

using System.IO;

using System.Web.UI.HtmlControls;

public partial class _Default : System.Web.UI.Page

{

    SqlConnection con = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["con"].ToString());

    protected void Page_Load(object sender, EventArgs e)

    {

        con.Open();

        string sql = "select * from Employee_Details";

        SqlCommand cmd = new SqlCommand(sql, con);

        DataSet ds = new DataSet();

        SqlDataAdapter da = new SqlDataAdapter();

        da.SelectCommand = cmd;

        da.Fill(ds);

        gv1.DataSource = ds;

        gv1.DataBind();

    }

    protected void btn1_Click(object sender, EventArgs e)

    {

        Response.AddHeader("content-disposition", "attachment; filename=Expport.xls");

        Response.ContentType = "application/ms-excel";

        StringWriter sWriter = new StringWriter();

        HtmlTextWriter hTextWriter = new HtmlTextWriter(sWriter);

        HtmlForm frm = new HtmlForm();

        gv1.Parent.Controls.Add(frm);

        frm.Attributes["runat"] = "server";

        frm.Controls.Add(gv1);

        frm.RenderControl(hTextWriter);

        // EmpReportGrid.RenderControl(hTextWriter);        

        Response.Write(sWriter.ToString());

        Response.End();

    }

    protected void Button1_Click(object sender, EventArgs e)

    {

        Response.AddHeader("content-disposition", "attachment; filename=Expport.doc");

        Response.ContentType = "application/ms-word";

        StringWriter sWriter = new StringWriter();

        HtmlTextWriter hTextWriter = new HtmlTextWriter(sWriter);

        HtmlForm frm = new HtmlForm();

        gv1.Parent.Controls.Add(frm);

        frm.Attributes["runat"] = "server";

        frm.Controls.Add(gv1);

        frm.RenderControl(hTextWriter);

        // EmpReportGrid.RenderControl(hTextWriter);        

        Response.Write(sWriter.ToString());

        Response.End();

    }

    protected void Button2_Click(object sender, EventArgs e)

    {

        Response.AddHeader("content-disposition", "attachment; filename=Expport.pdf");

        Response.ContentType = "application/pdf";

        StringWriter sWriter = new StringWriter();

        HtmlTextWriter hTextWriter = new HtmlTextWriter(sWriter);

        HtmlForm frm = new HtmlForm();

        gv1.Parent.Controls.Add(frm);

        frm.Attributes["runat"] = "server";

        frm.Controls.Add(gv1);

        frm.RenderControl(hTextWriter);

        // EmpReportGrid.RenderControl(hTextWriter);        

        Response.Write(sWriter.ToString());

        Response.End();

        

    }

}

web.config

<connectionStrings>

<add name="con" connectionString="Data Source=.;Initial Catalog=exp;Integrated Security=true;"/>

</connectionStrings>

Output