ASP.NET Excel导出编码问题

我在ASP.NET网站上做了一些Excel导出。
一切工作除了编码。当我在Excel中打开它，它看起来像这样：

Eingabe Kosten je Gerät Gerät:
Gerätebezeichnung:
Betriebsmittel Heizöl in €: 4
Dieselverbrauch in €: 4

这是我的代码：

Response.Clear();
Response.ContentType = "application/ms-excel";
Response.AddHeader("Content-Disposition","inline;filename=NachkalkGeraete.xls;");
var writer = new HtmlTextWriter(Response.Output);

SomeControl.RenderControl(writer); /* FormView,Table,DataGrid... */

Response.End();

我已经尝试明确设置Encoding ..但没有发生变化：

Response.Clear();
Response.ContentType = "application/vnd.ms-excel";
Response.AddHeader("Content-Disposition","attachment; filename=NachkalkGeraete.xls");

Response.BufferOutput = true;
Response.ContentEncoding = System.Text.Encoding.UTF8;
Response.Charset = "UTF-8";
EnableViewState = false;

System.IO.StringWriter tw = new System.IO.StringWriter();
HtmlTextWriter hw = new HtmlTextWriter(tw);

SomeControl.RenderControl(hw);

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

有什么问题吗？

解决方法

好吧，我发现，问题可能在excel文件的标题，它不包含BOM字节序列(在文件的开头表示使用的编码)。

所以我这样做，它适用于我：

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());

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();