下載時如何加密文件

Question

我在下載時加密文件時遇到問題。我正在使用此代碼將數據庫下載到excel文件中

GridView gv = new GridView();
                gv.DataSource = graphids.ToList();
                gv.DataBind();
                Response.ClearContent();
                Response.Buffer = true;
                Response.AddHeader("content-disposition", "attachment; filename=GraphTable.xls");
                Response.ContentType = "application/ms-excel";
                Response.Charset = "";
                StringWriter sw = new StringWriter();
                HtmlTextWriter htw = new HtmlTextWriter(sw);
                Response.Output.Write(sw.ToString());
                Response.Flush();
                Response.End();

現在，此代碼文件自動下載到我的PC的下載文件夾之后，現在我要在下載之前加密此xls文件嗎？

Answer 1

使用System.Security

FileStream fsInput = new FileStream(sInputFilename, 
                    FileMode.Open, 
                    FileAccess.Read);

    FileStream fsEncrypted = new FileStream(sOutputFilename, 
                    FileMode.Create, 
                    FileAccess.Write);

Answer 2

代替

StringWriter sw = new StringWriter();

您可以使用MemoryStream並將其包裝在CryptoStream中以加密數據...