Export a DataTable to Excel in ASP.NET

All spreadsheet applications (Excel, Calc etc.) understand semicolon separated files natively, so everyone can use this method – you don’t even have to use Excel for it to work.

public static void ExportToSpreadsheet(DataTable table, string name)
{
HttpContext context = HttpContext.Current;
context.Response.Clear();

foreach (DataColumn column in table.Columns)
{
context.Response.Write(column.ColumnName + ",");
}
context.Response.Write(Environment.NewLine);

foreach (DataRow row in table.Rows)
{
for (int i = 0; i < table.Columns.Count; i++)
{
context.Response.Write(row[i].ToString().Replace(",", string.Empty) + ",");
}
context.Response.Write(Environment.NewLine);
}

context.Response.ContentType = "text/csv";
context.Response.AppendHeader("Content-Disposition", "attachment; filename=" + name + ".csv");
context.Response.End();
}

Then just call this method and pass the DataTable and the filename as parameters.

ExportToSpreadsheet(table, "products");

The method is static so you can use it anywhere in a web application. Put it on a page, a HTTP Handler, add it to the App_Code folder or stick it in a separate assembly. As long as you call it from a web application it will work.