问下载多个csv文件在一个压缩文件夹在ASP .Net

EN

using System.IO;
using System.IO.Compression;

 protected void btnGenerate_Click(object sender, EventArgs e)
        {
            DataSet ds = getDataCSV();
            DataTable dt = ds.Tables[0];
            string csv = string.Empty;
            foreach (DataRow row in dt.Rows)
            {
                foreach (DataColumn column in dt.Columns)
                {
                    csv += row[column.ColumnName].ToString().Replace(",", ";") + ',';
                }
                csv += "\r\n";
            }
            DataTable dt1 = ds.Tables[1];
            string csv1 = string.Empty;
            foreach (DataRow row in dt1.Rows)
            {
                foreach (DataColumn column in dt1.Columns)
                {
                    csv1 += row[column.ColumnName].ToString().Replace(",", ";") + ',';
                }
                csv1 += "\r\n";
            }
            using (FileStream zipFile = File.Open("compressed_files.zip", FileMode.Create))
            {
                using (FileStream source1 = File.Open(csv, FileMode.Open, FileAccess.Read))
                {
                    using (FileStream source2 = File.Open(csv1, FileMode.Open, FileAccess.Read))
                    {
                        using (var archive = new Archive())
                        {

                            // Add files to the archive

                            archive.CreateEntry(csv, source1);

                            archive.CreateEntry(csv1, source2);


                            archive.Save(zipFile, new ArchiveSaveOptions() { Encoding = Encoding.ASCII, ArchiveComment = "two files are compressed in this archive" });

                        }
                    }
                }
            }
        }
    }