其实，利用ASP.NET输出指定内容的WORD、EXCEL、TXT、HTM等类型的文档很容易的。主要分为三步来完成。

　　一、定义文档类型、字符编码

Response.Clear();
Response.Buffer= true;
Response.Charset="utf-8";

//下面这行很重要， attachment 参数表示作为附件下载，您可以改成 online在线打开

//filename=FileFlow.xls 指定输出文件的名称，注意其扩展名和指定文件类型相符，可以为：.doc || .xls || .txt ||.htm

Response.AppendHeader("Content-Disposition","attachment;filename=FileFlow.xls");
Response.ContentEncoding=System.Text.Encoding.GetEncoding("utf-8");

//Response.ContentType指定文件类型 可以为application/ms-excel || application/ms-word || application/ms-txt || application/ms-html || 或其他浏览器可直接支持文档

Response.ContentType = "application/ms-excel";
this.EnableViewState = false;

　　二、定义一个输入流

System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);

　　三、将目标数据绑定到输入流输出

this.RenderControl(oHtmlTextWriter);

//this 表示输出本页，你也可以绑定datagrid,或其他支持obj.RenderControl()属性的控件

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

示例:

/// <summary>
        /// 导出数据到Excel表的方法
        /// <param name="dt">DataTable数据源</param>
        /// <param name="title">生成的Excel文件名</param>
        /// </summary>
        public static void Export(System.Data.DataTable dt, string title)
        {
            StringWriter sw = new StringWriter();

foreach (System.Data.DataColumn col in dt.Columns)
            {
                sw.Write(col.Caption + "\t");
            }
            sw.WriteLine();

foreach (System.Data.DataRow row in dt.Rows)
            {
                for (int i = 0; i < dt.Columns.Count; i++)
                {
                    sw.Write(row[i].ToString() + "\t");
                }
                sw.WriteLine();
            }

sw.Close();
            string filename = System.Web.HttpUtility.UrlPathEncode(title) + DateTime.Now.ToString("yyyyMMdd") + ".xls";
            HttpContext.Current.Response.AddHeader("content-disposition", "attachment;filename=" + filename);
            HttpContext.Current.Response.ContentType = "application/ms-excel";
            HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
            HttpContext.Current.Response.Write(sw);
            HttpContext.Current.Response.End();
        }