生成excel之后如何保存到服务器指定目录中？
小弟目前初学，碰到个问题请大家帮忙看下。 下面那个方法是把数据以ms-execl的格式，以Response输出到浏览器（客户端)，
怎么才能保存到服务器指定的目录中呢


public static void DataSetToExcel(DataSet ds)
{
DataTable dee = ds.Tables[0];
dee.DataSet.DataSetName = ds.ToString();
HttpContext.Current.Response.Clear();
System.IO.StringWriter sw = new System.IO.StringWriter();

//写数据，省略
...
...
...

sw.Close();
string ls_FileName = "attachment; filename=";
ls_FileName += FileHelper.GetRandom();
ls_FileName += ".xls";

HttpContext.Current.Response.AddHeader("Content-Disposition", ls_FileName);

HttpContext.Current.Response.ContentType = "application/vnd.ms-excel";

HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");

HttpContext.Current.Response.Write(sw);

HttpContext.Current.Response.Flush();
HttpContext.Current.Response.End();

[解决办法]
save 通过路径来保存！
[解决办法]
HttpContext.Current.Response.Write(sw);
改成
System.IO;File.WriteAllText(Server.MapPath("~/xx/x.xls"),sw)