java servlet response:

bf.append("Shipment No, STT No, WIN Event, DateTime, WOU Envent, DateTime");
					sbf.append('\n');

					for(int i=0;i<list.size();i++)
					{
						PrintStatisticsForm psrform = list.get(i);
						sbf.append(getCsvCommaString(psrform.getHawb()));
						sbf.append(getCsvCommaString(psrform.getStt()));
						sbf.append(getCsvCommaString(new HSSFRichTextString(psrform.getWinevent())));
						sbf.append(getCsvCommaString(new HSSFRichTextString(psrform.getWindatetime())));
						sbf.append(getCsvCommaString(new HSSFRichTextString(psrform.getWouevent())));
						sbf.append(getCsvCommaString(new HSSFRichTextString(psrform.getWoudatetime())));
						sbf.append('\n');
					} 
					sbf.append('\n');
					sbf.append('\n');
					sbf.append('\n');

	byte[] csvData = sbf.toString().getBytes();
					response.setHeader("Content-Disposition", "attachment;filename=Shipment Inventory Report.csv");   
					response.setContentLength(sbf.length());   
					response.setContentType("application/csv");   
					response.setCharacterEncoding("UTF-8");   
					response.getOutputStream().write(csvData);   
					response.getOutputStream().flush();   
					response.getOutputStream().close();

C# response

foreach (var totalCell in totalCellList)
{
totalContent.AppendFormat("\t{0},", totalCell.Value);
}

totalContent.AppendFormat("\t{0},", cellCountList.Values.Sum());
totalContent.AppendFormat("\t{0},", priceEvianBooCountList.Values.Sum());//依云及波多金额总计
totalContent.AppendFormat("\t{0},", pricefuWekoCountList.Values.Sum());//富维克金额总计
totalContent.AppendFormat("\t{0},", priceCountList.Values.Sum());//订单金额总计
sbContent.Append(totalContent.ToString());
//---------------------汇总行end------------------------//

sb.Append(sbContent.ToString());

var fileName = string.Format("{0}{1:yyyyMMddHHmmss}", (exporttype == 0 ? "日常报表_" : "详细报表_"), DateTime.Now);
userLogService.LogSuccessOperation(string.Format("导出报表[{0}.csv]!", fileName));

HttpContext.Current.Response.Clear();
HttpContext.Current.Response.ClearHeaders();
HttpContext.Current.Response.Buffer = false;
byte[] data = Encoding.Default.GetBytes(sb.ToString());
HttpContext.Current.Response.AddHeader("content-disposition", "attachment; filename=" + System.Web.HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8) + ".csv");
HttpContext.Current.Response.ContentType = "application/octet-stream";
HttpContext.Current.Response.ContentEncoding = Encoding.GetEncoding("utf-8");
HttpContext.Current.Response.BinaryWrite(data);
HttpContext.Current.Response.Flush();

//------------------------------------------

if (Request.Content.IsMimeMultipartContent())
{
var path = HttpContext.Current.Server.MapPath("~/App_Data");
var provider = new MultipartFormDataStreamProvider(path);
var task = Request.Content.ReadAsMultipartAsync(provider);
task.ContinueWith(t =>
{
if (t.IsFaulted || t.IsCanceled)
throw new HttpResponseException(HttpStatusCode.InternalServerError);
});
}
else
{
throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotAcceptable, "This request is not properly formatted"));
}