how do I zip multiple files using GZipStream in c#

I have created multiple csv files using datatable and want to zip all those file into one single zip file. Which is i'm doing all at dynamically. I tried following code ``` List<string> filestream = GenerateCSVfiles(dataSets); //Generate CSV files public List<string> GenerateCSVfiles(List<DataSet> dataSets) { List<string> filestream = new List<string>(); StringBuilder result = null; foreach (DataSet dataSet in dataSets) { result = new StringBuilder(); System.Data.DataTable dataTable = dataSet.Tables[0]; foreach (DataColumn colm in dataTable.Columns) { result.Append(colm.ColumnName+","); } result.Append("\n"); //create csv file foreach (DataRow row in dataTable.Rows) { for (int i = 0; i < dataTable.Columns.Count; i++) { result.Append(row[i].ToString()); result.Append(i == dataTable.Columns.Count - 1 ? "\n" : ","); } } filestream.Add(result.ToString()); } return filestream; } ``` Now in `List<filestream>` I have all 2 file data want to create 2 different `.csv` files and create one `temp.gz` file dynamically How can I do this ? On `ActionResult` method I tried following code to generate .zip file but it is corrupted ``` return File(CompressStringToFile("temp.gz", filestream), System.Net.Mime.MediaTypeNames.Application.Zip, "temp.gz"); ``` // zip file generation code ``` public byte[] CompressStringToFile(string fileName, List<string> filestream) { MemoryStream f2 = new MemoryStream(); FileStream fs = new FileStream(); GZipStream gz = new GZipStream(f2, CompressionMode.Compress, false); foreach (string oStr in filestream) { byte[] b = GetBytes(oStr); gz.Write(b, 0, b.Length); } return f2.ToArray(); } ``` Correct me to generate .zip file. (with inside 2 .csv files)