就像这样使用

Response.Clear();
Response.ContentType = "application/CSV";
Response.AddHeader("content-disposition", "attachment; filename=\"" + filename + ".csv\"");
Response.Write(t.ToString());
Response.End();

对于c# MVC 4.5，你需要这样做:

Response.Clear();
Response.ContentType = "application/CSV";
Response.AddHeader("content-disposition", "attachment; filename=\"" + fileName + ".csv\"");
Response.Write(dataNeedToPrint);
Response.End();
return new EmptyResult();  //this line is important else it will not work.

就像这样使用

Response.Clear();
Response.ContentType = "application/CSV";
Response.AddHeader("content-disposition", "attachment; filename=\"" + filename + ".csv\"");
Response.Write(t.ToString());
Response.End();

多年来，我一直在为此打磨一套完美的头文件，在我所知道的所有浏览器中都能出色地工作

// these headers avoid IE problems when using https:
// see http://support.microsoft.com/kb/812935
header("Cache-Control: must-revalidate");
header("Pragma: must-revalidate");

header("Content-type: application/vnd.ms-excel");
header("Content-disposition: attachment; filename=$filename.csv");

在ASP.net MVC中，你可以使用FileContentResult和File方法:

public FileContentResult DownloadManifest() {
    byte[] csvData = getCsvData();
    return File(csvData, "text/csv", "filename.csv");
}

使用text/csv作为内容类型。