string root = Server.MapPath("/");//网站根目录
string filename = DateTime.Now.ToString("YYYYMMddhhmmss")+".xls";
string saveroot = root+"download//"+filename;
string contect = "项目1/t项目2/t项目3/r/n111/t222/t333";
//StreamWriter sw = File.CreateText(saveroot);
File.AppendAllText(saveroot, contect,Encoding.UTF8);
Response.Redirect("//download//" + filename);
string filename = DateTime.Now.ToString("YYYYMMddhhmmss")+".xls";
string saveroot = root+"download//"+filename;
string contect = "项目1/t项目2/t项目3/r/n111/t222/t333";
//StreamWriter sw = File.CreateText(saveroot);
File.AppendAllText(saveroot, contect,Encoding.UTF8);
Response.Redirect("//download//" + filename);