DataTable 导出 excel ， 可以自定义列名，没有繁琐的引用

/// <summary>
        /// 由DataTable导出Excel
       /// </summary>
       /// <param name="p"></param>
       /// <param name="dt"></param>
       /// <param name="fileName"></param>
        /// <param name="b"> true为datatable列名  false为自定义列名</param>
       /// <param name="colHeaders"> 自定义列名 已|分割</param>
        public static void DataTableToExcel(Page p, DataTable dt, string fileName,bool b, string colHeaders)
        {
            HttpResponse resp;
            resp = p.Response;
            resp.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
            resp.AppendHeader("Content-Disposition", "attachment;filename=" +  HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
            string  ls_item = "";
            int cl = dt.Columns.Count;
            ////定义表对象与行对象，同时用DataSet对其值进行初始化
            //DataTable dt = ds.Tables[0];
            DataRow[] myRow = dt.Select();//可以类似dt.Select("id>10")之形式达到数据筛选目的
            int i = 0;

            //取得数据表各列标题，各标题之间以t分割，最后一个列标题后加回车符

            //取datatable里的列名
            if (b)
            {
                for (i = 0; i < cl; i++)
                {
                    if (i == (cl - 1))//最后一列，加n
                    {
                        colHeaders += dt.Columns[i].Caption.ToString() + "\n";
                    }
                    else
                    {
                        colHeaders += dt.Columns[i].Caption.ToString() + "\t";
                    }
                }
            }
            else
            {
                string[] colHeaderList = colHeaders.Split(new string[] { "|" }, StringSplitOptions.RemoveEmptyEntries);
                colHeaders = "";
                //自定义列名
                for (i = 0; i < colHeaderList.Length; i++)
                {
                    if (i == (colHeaderList.Length - 1))
                    {
                        colHeaders += colHeaderList[i] + "\n";
                    }
                    else
                    {
                        colHeaders += colHeaderList[i] + "\t";
                    }

                }
            }
            resp.Write(colHeaders);

            //逐行处理数据
            foreach (DataRow row in myRow)
            {

                for (i = 0; i < cl; i++)
                {
                    if (i == (cl - 1))
                    {
                        ls_item += row[i].ToString() + "\n";
                    }
                    else
                    {
                        ls_item += row[i].ToString() + "\t";
                    }

                }
                resp.Write(ls_item);
                ls_item = "";

            }
            resp.End();
        }