Hi, You can achieve this using different ways. If your grid contains uri of the file you want to download then just call below function by passing download file path as a parameter.
public void DownloadFile(string filePath)
{
Response.ClearContent();
Response.Clear();
Response.ContentType = "APPLICATION/OCTET-STREAM";
String Header = "Attachment; Filename=\"" + "FileName.pdf" + "\"";
Response.AppendHeader("Content-Disposition", Header);
System.IO.FileInfo Dfile = new System.IO.FileInfo(filePath);
Response.WriteFile(Dfile.FullName);
Response.End();
}
I hope this will help you. :)