导出主要考虑响应流的问题

   curContext.Response.ContentType = "application/vnd.ms-excel";

   curContext.Response.AddHeader("Content-Disposition", "attachment; filename=" + filename + ".xls");

   curContext.Response.ContentEncoding = System.Text.Encoding.UTF8;

public void ExportExecl(DataTable dtData)

        {

            System.Web.UI.WebControls.DataGrid dgExport = null;

            // 当前对话

            System.Web.HttpContext curContext = System.Web.HttpContext.Current;

            // IO用于导出并返回excel文件

            System.IO.StringWriter strWriter = null;

            System.Web.UI.HtmlTextWriter htmlWriter = null;

            if (dtData != null)

            {

                // 设置编码和附件格式

                DateTime dt = DateTime.Now;

                string filename = dt.Year.ToString() + dt.Month.ToString() + dt.Day.ToString() + dt.Hour.ToString() + dt.Minute.ToString() + dt.Second.ToString();

                curContext.Response.ContentType = "application/vnd.ms-excel";

                curContext.Response.AddHeader("Content-Disposition", "attachment; filename=" + filename + ".xls");

                curContext.Response.ContentEncoding = System.Text.Encoding.UTF8;

                curContext.Response.Charset = "";

                // 导出excel文件

                strWriter = new System.IO.StringWriter();

                htmlWriter = new System.Web.UI.HtmlTextWriter(strWriter);

                // 为了解决dgData中可能进行了分页的情况，需要重新定义一个无分页的DataGrid

                dgExport = new System.Web.UI.WebControls.DataGrid();

                dgExport.DataSource = dtData.DefaultView;

                dgExport.AllowPaging = false;

                dgExport.DataBind();

                // 返回客户端

                dgExport.RenderControl(htmlWriter);

                curContext.Response.Write(strWriter.ToString());

                curContext.Response.End();

            }

        }