export html table to excel file encoding

Question

Ive got task to write code to export html table with headers to excel.

What I came up with is serverSide code like this:

Response.Clear();
    Response.AddHeader("content-disposition", "attachment;filename=myexcel.xls");
    Response.ContentType = "application/ms-excel";
    System.IO.StringWriter sw = new System.IO.StringWriter();
    System.Web.UI.HtmlTextWriter hw = new HtmlTextWriter(sw);
    tbPanel.RenderControl(hw);
    Response.Write(sw.ToString());
    Response.End();

It works quite well but there are some utf-8 characters (russian language) which arent displayed correclty in excel file.

Any ideas that can I do about it ?

Thanks for help

Answer 1

Change your code to the following:

Response.Clear();
Response.AddHeader("content-disposition","attachment;filename=myexcel.xls");   
Response.ContentType = "application/ms-excel";
Response.ContentEncoding = System.Text.Encoding.Unicode;
Response.BinaryWrite(System.Text.Encoding.Unicode.GetPreamble());

System.IO.StringWriter sw = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter hw = new HtmlTextWriter(sw);

FormView1.RenderControl(hw);

Response.Write(sw.ToString());
Response.End();

Edit

While I was posting my answer, I saw that you already figured out the same solution. The error message that you're seeing is explained here: Excel 2007 Extension Warning On Opening Excel Workbook from a Web Site and, unfortunately, there is no way to workaround it.

From the post:

The alert prompt is "by design", but the interaction of the cancel action and IE's attempt to open the file again is a known problem under investigation for a future fix.

Answer 2

Ive added:

    Response.Clear();
Response.AddHeader("content-disposition","attachment;filename=Test.xls");   
Response.ContentType = "application/ms-excel";
Response.ContentEncoding = System.Text.Encoding.Unicode;
Response.BinaryWrite(System.Text.Encoding.Unicode.GetPreamble());

And now it works ok except there is an warning while opening excel file thjere is an error that the file has got different format than the extension. Can I get Rid of that ?