利用Response.ContentType 属性，设置为application/vnd.ms-excel，将文本数据以microsoft excel的格式输出（Response）到客户端。
如，导出DataGrid:
1 //要导出的DataGrid控件 2 3 protected void Button2_Click(object sender, EventArgs e) 4 5 { 6 7 //要导出的控件 8 9 System.Web.UI.Control ctl = this.Label1; 10 11 12 13 //输出属性 14 15 HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=Excel.xls"); 16 17 HttpContext.Current.Response.Charset = "UTF-8"; 18 19 HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.Default; 20 21 HttpContext.Current.Response.ContentType = "application/ms-excel"; 22 23 24 25 //输出空间内容到HtmlTextWriter 26 27 ctl.Page.EnableViewState = false; 28 29 System.IO.StringWriter tw = new System.IO.StringWriter(); 30 31 System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter(tw); 32 33 ctl.RenderControl(hw); 34 35 36 37 //输出HtmlTextWriter 38 39 HttpContext.Current.Response.Write(tw.ToString()); 40 41 HttpContext.Current.Response.End(); 42 43 }
使用这种方法，可以将大部分控件的数据都导入到Excel文件中。如Literal、GridView、Repeater、Label，只要这些控件中的数据是格式良好的表格，导出的Excel格式也是以表格数据形式展现。
将上边的代码直接写入到Page_Load中，可以将整个页面下载为Excel文件.
1 protected void Page_Load(object sender, EventArgs e) 2 3 { 4 5 if (!IsPostBack) 6 7 { 8 9 Response.Clear(); 10 11 Response.Buffer = true; 12 13 Response.AppendHeader("Content-Disposition", "attachment;filename=" + DateTime.Now.ToString("yyyyMMdd") + ".xls"); 14 15 Response.ContentEncoding = System.Text.Encoding.UTF8; 16 17 Response.ContentType = "application/vnd.ms-excel"; 18 19 this.EnableViewState = false; 20 21 } 22 23 }