How to download a file using datalist in asp.net

You need to give the file path of download file to Button. You can bind the file path to CommandArgument of button, then handle its Click event or ItemCommand event of DataList to do downloading. protected void DataList1_ItemCommand(object sender, DataListCommandEventArgs e) { if (e.CommandName == "download") { string file = e.CommandArgument.ToString(); DownloadFile(file); } } protected void DownloadFile(string filepath) { System.IO.Stream iStream = null; // Buffer to read 10K bytes in chunk: byte[] buffer = new Byte[10000]; // Length of the file: int length; // Total bytes to read: long dataToRead; // Identify the file name. string filename = System.IO.Path.GetFileName(filepath); try { // Open the file. iStream = new System.IO.FileStream(filepath, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read); // Total bytes to read: dataToRead = iStream.Length; Response.ContentType = "application/octet-stream"; Response.AddHeader("Content-Disposition", "inline; filename=" + filename); // Read the bytes. while (dataToRead > 0) { // Verify that the client is connected. if (Response.IsClientConnected) { // Read the data in buffer. length = iStream.Read(buffer, 0, 10000); // Write the data to the current output stream. Response.OutputStream.Write(buffer, 0, length); // Flush the data to the HTML output. Response.Flush(); buffer = new Byte[10000]; dataToRead = dataToRead - length; } else { //prevent infinite loop if user disconnects dataToRead = -1; } } } catch (Exception ex) { // Trap the error, if any. Response.Write("Error : " + ex.Message); } finally { if (iStream != null) { //Close the file. iStream.Close(); } } }