公共代码帮助类：下载页面、导出Excel（不带表头）、导出Execl（带表头）、 导出CSV、实现对IList到DataSet的转换

using System;
using System.Data;
using System.Web;
using System.Net;
using System.Text;
using System.IO;
using System.Collections.Generic;

namespace IWOMTracker.Common
{
    public class PageText
    {
        /// <summary>
        /// 下载页面
        /// </summary>
        /// <param name="strUrl"></param>
        /// <returns></returns>
        public static string GetPageData(string strUrl)
        {
            string text = "";
            if (strUrl == "")
            {
                return "";
            }
            WebResponse response = null;
            Stream responseStream = null;
            StreamReader reader = null;
            try
            {
                response = WebRequest.Create(strUrl).GetResponse(); //创建一个合适的对象/ 2获得村服务器上得到的数据
                responseStream = response.GetResponseStream(); //得到数据流
                reader = new StreamReader(responseStream, Encoding.UTF8);
                string txt = reader.ReadToEnd();
                string encod = txt.Substring(txt.IndexOf("<meta"));
                encod = encod.Substring(encod.IndexOf("charset=") + 8, 20);
                response = WebRequest.Create(strUrl).GetResponse();
                responseStream = response.GetResponseStream();
                reader = new StreamReader(responseStream, Encoding.UTF8);
                if (encod.ToLower().IndexOf("utf-8") >= 0)
                {
                    reader = new StreamReader(responseStream, Encoding.GetEncoding("utf-8"));
                }
                else if (encod.ToLower().IndexOf("gb2312") >= 0)
                {
                    reader = new StreamReader(responseStream, Encoding.GetEncoding("gb2312"));
                }
                else if (encod.ToLower().IndexOf("utf8") >= 0)
                {
                    reader = new StreamReader(responseStream, Encoding.GetEncoding("utf-8"));
                }
                else if (encod.ToLower().IndexOf("gbk") >= 0)
                {
                    reader = new StreamReader(responseStream, Encoding.GetEncoding("gbk"));
                }
                else
                {
                    reader = new StreamReader(responseStream, Encoding.Default);
                }
                try
                {
                    return reader.ReadToEnd();
                }
                catch
                {
                    return "";
                }
            }
            catch (Exception exn)
            {
                if (exn.Message.ToString().IndexOf("远程服务器返回错误: (503) 服务器不可用") > -1)
                    text = "beifeng";
                else
                    text = "";
            }
            finally
            {
                if (reader != null)
                {
                    reader.Close();
                }
                if (responseStream != null)
                {
                    responseStream.Close();
                }
                if (response != null)
                {
                    response.Close();
                }
            }
            return text;
        }

        public static string GetWebContent(string Url)
        {
            string strResult = "";
            try
            {
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
                //声明一个HttpWebRequest请求
                request.Method = "GET";
                request.SendChunked = false;

                request.Timeout = 10000;
                //设置连接超时时间
                request.Headers.Set("Pragma", "no-cache");
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                Stream streamReceive = response.GetResponseStream();
                Encoding encoding = Encoding.GetEncoding("GB2312");
                StreamReader streamReader = new StreamReader(streamReceive, encoding);
                strResult = streamReader.ReadToEnd();
                response.Close();
                streamReader.Close();
            }
            catch (Exception ex)
            {
                throw new Exception("抓取数据出错" + ex.Message);
            }
            return strResult;
        }

        /// <summary>
        /// 导出Excel（不带表头）
        /// </summary>
        /// <param name="dt"></param>
        /// <param name="FileName"></param>
        /// <param name="response"></param>
        public static void CreateExcel(DataTable dt, string FileName, HttpResponse response)
        {
            HttpResponse resp;
            resp = response;
            FileName = System.Web.HttpUtility.UrlEncode(System.Text.Encoding.UTF8.GetBytes(FileName));
            resp.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
            resp.AppendHeader("Content-Disposition", "attachment;filename=" + FileName + ".xls");
            string ls_item = "";

            //定义表对象与行对象，同时用DataSet对其值进行初始化 

            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;
            int cl = dt.Columns.Count;
            
            //向HTTP输出流中写入取得的数据信息 

            //逐行处理数据   
            foreach (DataRow row in myRow)
            {
                //当前行数据写入HTTP输出流，并且置空ls_item以便下行数据     
                for (i = 0; i < cl; i++)
                {
                    if (i == (cl - 1))//最后一列，加n
                    {
                        ls_item += row[i].ToString().Replace("\n", " ").Replace("\"", "\"\"") + "\n";
                    }
                    else
                    {
                        ls_item += row[i].ToString().Replace("\n", " ").Replace("\"", "\"\"") + "\t";
                    }

                }
                resp.Write(ls_item.Replace("\r", " "));
                ls_item = "";

            }
            resp.End();
        }

        /// <summary>
        /// 导出Execl（带表头）
        /// </summary>
        /// <param name="dt"></param>
        /// <param name="FileName"></param>
        /// <param name="response"></param>
        public static void CreateExcel2(DataTable dt, string FileName, HttpResponse response)
        {
            HttpResponse resp;
            resp = response;
            FileName = System.Web.HttpUtility.UrlEncode(System.Text.Encoding.UTF8.GetBytes(FileName));
            resp.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
            resp.AppendHeader("Content-Disposition", "attachment;filename=" + FileName + ".xls");
            string colHeaders = "", ls_item = "";

            //定义表对象与行对象，同时用DataSet对其值进行初始化 

            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;
            int cl = dt.Columns.Count;

            //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 
            for (i = 0; i < cl; i++)
            {
                if (i == (cl - 1))//最后一列，加n
                {
                    colHeaders += dt.Columns[i].Caption.ToString().Replace("\n", " ").Replace("\"", "\"\"") + "\n";
                }
                else
                {
                    colHeaders += dt.Columns[i].Caption.ToString().Replace("\n", " ").Replace("\"", "\"\"") + "\t";
                }

            }
            resp.Write(colHeaders.Replace("\r", " "));
            //向HTTP输出流中写入取得的数据信息 

            //逐行处理数据   
            foreach (DataRow row in myRow)
            {
                //当前行数据写入HTTP输出流，并且置空ls_item以便下行数据     
                for (i = 0; i < cl; i++)
                {
                    if (i == (cl - 1))//最后一列，加n
                    {
                        ls_item += row[i].ToString().Replace("\n", " ").Replace("\"", "\"\"") + "\n";
                    }
                    else
                    {
                        ls_item += row[i].ToString().Replace("\n", " ").Replace("\"", "\"\"") + "\t";
                    }

                }
                resp.Write(ls_item.Replace("\r", " "));
                ls_item = "";

            }
            resp.End();
        }

        /// <summary>
        /// 导出CSV
        /// </summary>
        /// <param name="tb">DataTable</param>
        /// <param name="response">Page.Response</param>
        /// <param name="fileName">导出文件名</param>
        /// <param name="isHeader">是否导出tb表头</param>
        public static void ExportCSV(DataTable tb, HttpResponse response, string fileName, bool isHeader)
        {
            string data = "";

            //写出列名
            if (isHeader)
            {
                foreach (DataColumn column in tb.Columns)
                {
                    data += column.ColumnName.Replace(",", "，") + ",";
                }
                data += "\n";
            }

            //写出数据
            foreach (DataRow row in tb.Rows)
            {
                foreach (DataColumn column in tb.Columns)
                {
                    data += row[column].ToString().Replace(",", "，") + ",";
                }
                data += "\n";
            }
            data += "\n";

            string temp = string.Format("attachment;filename={0}", fileName + ".csv");
            response.ClearHeaders();
            response.AppendHeader("Content-disposition", temp);
            response.Charset = "gb2312";
            response.ContentType = "application/ms-excel";
            response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
            response.Write(data);
            response.End();
        }

        /// <summary>
        /// 实现对IList到DataSet的转换
        /// </summary>
        /// <param name="list">待转换的IList</param>
        /// <returns>转换后的DataSet</returns>
        public static DataSet IListToDataSet<T>(IList<T> list, Type type)
        {
            if (list == null || list.Count <= 0)
            {
                return null;
            }

            DataSet ds = new DataSet();
            DataTable dt = new DataTable(type.Name);
            DataColumn column;
            DataRow row;

            System.Reflection.PropertyInfo[] myPropertyInfo = type.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance);

            foreach (T t in list)
            {
                if (t == null)
                {
                    continue;
                }

                row = dt.NewRow();

                for (int i = 0, j = myPropertyInfo.Length; i < j; i++)
                {
                    System.Reflection.PropertyInfo pi = myPropertyInfo[i];

                    string name = pi.Name;

                    if (dt.Columns[name] == null)
                    {
                        column = new DataColumn(name, pi.PropertyType);
                        dt.Columns.Add(column);
                    }

                    row[name] = ((object[])(object)t)[i] == null ? DBNull.Value : ((object[])(object)t)[i];
                }

                dt.Rows.Add(row);
            }

            ds.Tables.Add(dt);

            return ds;
        }
    }
}