Response.ContentType = "application/vnd.ms-excel";
The ContentType property specifies the HTTP content type for the response. If no ContentType is specified, the default is text/HTML.
Get all your data in a DataGrid
and then get it from it can be done with:
DataGrid.RenderControl
Outputs server control content to a provided HtmlTextWriter
object and stores tracing information about the control if tracing is enabled.
SqlConnection cn = new SqlConnection("yourconnectionstring");
cn.Open();
SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM Users", cn);
DataTable dt = new DataTable();
da.Fill(dt);
DataGrid dg = new DataGrid();
dg.DataSource = dt;
dg.DataBind();
System.IO.StringWriter tw = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter(tw);
dg.RenderControl(hw);
cn.Close();
Response.Clear();
Response.ContentType = "application/vnd.ms-excel";
this.EnableViewState = false;
Response.Write(tw.ToString());
Response.End();