Export ASP.Net GridView with TemplateField columns to CSV (Text) file using C#

Hi Vincenzo67,

Refer below sample.

Database

For this example I have used of Northwind database that you can download using the link given below.

Download Northwind Database

HTML

<asp:GridView ID="GridView1" HeaderStyle-BackColor="#3AC0F2" HeaderStyle-ForeColor="White"
    RowStyle-BackColor="#A1DCF2" AlternatingRowStyle-BackColor="White" AlternatingRowStyle-ForeColor="#000"
    runat="server" AutoGenerateColumns="false" AllowPaging="true" OnPageIndexChanging="OnPageIndexChanging">
    <Columns>
        <asp:TemplateField HeaderText="No." ItemStyle-CssClass="ddl_Class_new" ItemStyle-HorizontalAlign="Center">
            <ItemTemplate>
                <%#String.Format("{0:N0}",Container.DataItemIndex + 1)%>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:BoundField DataField="ContactName" HeaderText="Contact Name" ItemStyle-Width="150px" />
        <asp:TemplateField HeaderText="City">
            <ItemTemplate>
                <asp:HyperLink ID="lnkCity" runat="server" NavigateUrl="#" Text='<%# Eval("City") %>'></asp:HyperLink>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Country">
            <ItemTemplate>
                <asp:TextBox ID="txtCountry" runat="server" Text='<%# Eval("Country") %>'></asp:TextBox>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="CheckBox">
            <ItemTemplate>
                <asp:CheckBox ID="CheckBox1" runat="server" Text="CheckBox" />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="RadioButton">
            <ItemTemplate>
                <asp:RadioButton ID="RadioButton1" runat="server" Text="Radio" />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Button">
            <ItemTemplate>
                <asp:Button ID="Button1" runat="server" Text="Button" />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="LinkButton">
            <ItemTemplate>
                <asp:LinkButton ID="LinkButton1" runat="server" Text="LinkButton" />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Label">
            <ItemTemplate>
                <asp:Label ID="lbl" runat="server" Text='<%# Eval("CompanyName") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>
<br />
<asp:Button ID="btnExport" runat="server" Text="Export To Excel" OnClick="ExportToExcel" />

Namespace

using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Text;

Code

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

private void BindGrid()
{
    string strConnString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(strConnString))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT * FROM Customers"))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                cmd.Connection = con;
                sda.SelectCommand = cmd;
                using (DataTable dt = new DataTable())
                {
                    sda.Fill(dt);
                    GridView1.DataSource = dt;
                    GridView1.DataBind();
                }
            }
        }
    }
}

protected void OnPageIndexChanging(object sender, GridViewPageEventArgs e)
{
    GridView1.PageIndex = e.NewPageIndex;
    this.BindGrid();
}

protected void ExportToExcel(object sender, EventArgs e)
{
    Response.Clear();
    Response.Buffer = true;
    Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.csv");
    Response.Charset = "";
    Response.ContentType = "application/text";

    //To Export all pages
    GridView1.AllowPaging = false;
    this.BindGrid();

    StringBuilder sb = new StringBuilder();
    for (int k = 0; k < GridView1.Columns.Count; k++)
    {
        sb.Append(GridView1.Columns[k].HeaderText + ',');
    }
    sb.Append("\r\n");
    foreach (GridViewRow row in GridView1.Rows)
    {
        foreach (TableCell cell in row.Cells)
        {
            string text = "";
            if (cell.Controls.Count > 0)
            {
                foreach (Control control in cell.Controls)
                {
                    switch (control.GetType().Name)
                    {
                        case "Label":
                            text = (control as Label).Text;
                            break;
                        case "HyperLink":
                            text = (control as HyperLink).Text;
                            break;
                        case "TextBox":
                            text = (control as TextBox).Text;
                            break;
                        case "LinkButton":
                            text = (control as LinkButton).Text;
                            break;
                        case "Button":
                            text = (control as Button).Text;
                            break;
                        case "CheckBox":
                            text = (control as CheckBox).Text;
                            break;
                        case "RadioButton":
                            text = (control as RadioButton).Text;
                            break;
                        case "DataBoundLiteralControl":
                            text = (control as DataBoundLiteralControl).Text.Trim();
                            break;
                    }
                }
            }
            else
            {
                text = cell.Text;
            }
            sb.Append(text + ',');
        }
        sb.Append("\r\n");

    }
    Response.Output.Write(sb.ToString());
    Response.Flush();
    Response.End();
}

Screenshot