Ciao,
prova questo esempio:
N.B prima devi impostare la connessione al database e la query SQL
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Text" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected System.Web.UI.HtmlControls.HtmlForm form2;
string filename = "Export.xls";
bool clickExport = false;
protected void Page_Load(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection("Data Source=.\\SQLEXPRESS;Initial Catalog=Northwind;Integrated Security=True");
SqlCommand selectCmd = new SqlCommand("SELECT * FROM Products", conn);
SqlDataAdapter dataAdpt = new SqlDataAdapter(selectCmd);
DataTable dt = new DataTable();
dataAdpt.Fill(dt);
DataGrid1.DataSource = dt;
DataGrid1.DataBind();
}
protected void Page_PreRender(object sender, EventArgs e)
{
if (clickExport)
{
form2 = new System.Web.UI.HtmlControls.HtmlForm();
this.Page.Controls.Add(form2);
form2.Controls.Clear();
form2.Controls.Add(DataGrid1);
form2.EnableViewState = false;
}
}
protected override void Render(HtmlTextWriter writer)
{
if (clickExport)
{
System.Text.StringBuilder sb = new System.Text.StringBuilder();
System.IO.StringWriter sw = new System.IO.StringWriter(sb);
HtmlTextWriter hw = new HtmlTextWriter(sw);
form2.RenderControl(hw);
//Recupera l'HTML di form2
string htmlForm2 = sb.ToString();
//Rimuove il secondo form
this.Page.Controls.Remove(form2);
Response.Buffer = true;
Response.Clear();
Response.ContentType = "application/vnd.ms-excel";
Response.AddHeader("Content-Disposition", "attachment;filename=" + filename);
Response.Charset = "";
Response.Cache.SetCacheability(HttpCacheability.NoCache);
// Passa l'HTML da esportare
Response.Write("<html><body>");
Response.Write(htmlForm2.ToString());
Response.Write("</body></html>");
Response.End();
}
// Si lascia inalterato HtmlTextWriter della pagina
base.Render(writer);
}
protected void Button1_Click(object sender, EventArgs e)
{
clickExport = true;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Pagina senza titolo</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" />
<asp:DataGrid ID="DataGrid1" runat="server" AutoGenerateColumns="True">
</asp:DataGrid>
</div>
</form>
</body>
</html>