StringWriter sw = new StringWriter();
HtmlTextWriter htw = new HtmlTextWriter(sw);
this.dg_Test.RenderControl(htw);
Response.ContentType = "appliction/ms-excel";
Response.AddHeader("ContentDisposition", "online;test.xls");
Response.ContentEncoding=System.Text.Encoding.GetEncoding("utf-8");  
Response.Write(sw.ToString());
这样的代码,运行后还是提示下载文档。为什么不能直接在线打开?