how to export grid view data into MS excel file in asp.net using c#

In this web programming tutorial we will learn that how we can export grid view data into MS excel file in asp.net using c#

Code for .cs file

protected void btnExportExcel_Click(object sender, EventArgs e)
{
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);
 
GridView1.AllowPaging = false;
GridView1.DataBind();
 
//Change the Header Row back to white color
GridView1.HeaderRow.Style.Add("background-color", "#FFFFFF");
 
//Apply style to Individual Cells
GridView1.HeaderRow.Cells[0].Style.Add("background-color", "green");
GridView1.HeaderRow.Cells[1].Style.Add("background-color", "green");
GridView1.HeaderRow.Cells[2].Style.Add("background-color", "green");
GridView1.HeaderRow.Cells[3].Style.Add("background-color", "green");  
 
for (int i = 0; i < GridView1.Rows.Count;i++ )
{
    GridViewRow row = GridView1.Rows[i];
 
    //Change Color back to white
    row.BackColor = System.Drawing.Color.White;
 
    //Apply text style to each Row
    row.Attributes.Add("class", "textmode");
 
    //Apply style to Individual Cells of Alternating Row
    if (i % 2 != 0)
    {
        row.Cells[0].Style.Add("background-color", "#C2D69B");
        row.Cells[1].Style.Add("background-color", "#C2D69B");
        row.Cells[2].Style.Add("background-color", "#C2D69B");
        row.Cells[3].Style.Add("background-color", "#C2D69B");  
    }
}
GridView1.RenderControl(hw);
 
//style to format numbers to string
string style = @"";
Response.Write(style);
Response.Output.Write(sw.ToString());
Response.Flush();
Response.End();
}

To avoid the error you will need to add this event which ensures that the GridView is Rendered before exporting.

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