How to Export Gridview contain to Excel file using C# in ASP.Net

Hi sp09,

I have checked your code and working with no issue.

HTML

<asp:GridView ID="grdStudent" runat="server" AutoGenerateColumns="false" AllowPaging="true"
    OnPageIndexChanging="OnPageIndexChanging">
    <Columns>
        <asp:BoundField DataField="ContactName" HeaderText="Contact Name" />
        <asp:BoundField DataField="City" HeaderText="City" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
    </Columns>
</asp:GridView>
<br />
<asp:ImageButton ImageUrl="" AlternateText="Export" runat="server" OnClick="imgBtnPDF_Click" />

Code

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        this.GrdBind();
    }
}

private void GrdBind()
{
    string strConnString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(strConnString))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT TOP 20 * FROM Customers"))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                cmd.Connection = con;
                sda.SelectCommand = cmd;
                using (DataTable dt = new DataTable())
                {
                    sda.Fill(dt);
                    grdStudent.DataSource = dt;
                    grdStudent.DataBind();
                }
            }
        }
    }
}

public void ExportGridToExcel(GridView grd)
{
    Response.Clear();
    Response.Buffer = true;
    Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.xls");
    Response.Charset = "";
    Response.ContentType = "application/vnd.ms-excel";
    StringWriter sw = new StringWriter();
    HtmlTextWriter hw = new HtmlTextWriter(sw);
    grd.AllowPaging = false;
    GrdBind();
    grd.RenderControl(hw);
    string style = @"<style> .textmode { mso-number-format:\@; } </style>";
    Response.Write(style);
    Response.Output.Write(sw.ToString());
    Response.Flush();
    Response.End();
}

public override void VerifyRenderingInServerForm(Control control)
{
    /* Verifies that the control is rendered */
}

protected void imgBtnPDF_Click(object sender, ImageClickEventArgs e)
{
    ExportGridToExcel(grdStudent);
    grdStudent.AllowPaging = true;
    GrdBind();
}

protected void OnPageIndexChanging(object sender, GridViewPageEventArgs e)
{
    grdStudent.PageIndex = e.NewPageIndex;
    this.GrdBind();
}

Screenshot