IMEX.mes.web/wwwroot/mes/exportExcel.ashx

<%@ WebHandler Language="C#" Class="exportExcel" %>

using System;
using System.Web;
using System.Data;
using System.Collections;
using System.Data.OleDb;
using Oracle.ManagedDataAccess.Client;
using System.Reflection;
using System.Text;
using System.IO;
using Curtain.DataAccess;
using DK.XuWei.WebMes;

public class exportExcel : IHttpHandler
{

    public void ProcessRequest(HttpContext context)
    {
        context.Response.ContentType = "text/plain";

        using (IDataAccess conn = DataAccess.Create())
        {

            OracleDataReader dr = (OracleDataReader)conn.ExecuteReader(@"
				SELECT 
					*
				FROM
					TP_MST_USER
				WHERE
					VALUEFLAG = '1'
					AND USERID < @USERID@ 
				",
                new CDAParameter("USERID", "10")
            );

            string excelFile = "/export/export.xls";
            int result = ExportToCsv(dr, HttpContext.Current.Server.MapPath(excelFile));

            if(result == 1)
            {
                context.Response.Write(new JsonResult(excelFile) { message = "数据导出成功！"}.ToJson());
                context.Response.Redirect(excelFile);
            }
            else
                context.Response.Write(new JsonResult(JsonStatus.error) { message = "数据导出失败！"}.ToJson());

        }

    }

    /// <summary>
    /// 导出到Csv文件
    /// </summary>
    /// <param name="dataReader">SqlDataReader</param>
    /// <param name="csvFile">csv文件</param>
    /// <returns></returns>
    public static int ExportToCsv(OracleDataReader dataReader, string csvFile)
    {
        try
        {
            string headerStr = "";
            StringBuilder dataStr = new StringBuilder("");

            //读标题列
            for (int i = 0; i < dataReader.FieldCount; i++)
            {
                if (i > 0) headerStr += ",";
                headerStr += "\"" + dataReader.GetName(i) + "\"";
            }
            headerStr += "\n";
            dataStr.Append(headerStr);

            //读数据列
            while (dataReader.Read())
            {
                for (int j = 0; j < dataReader.FieldCount; j++)
                {
                    if (j > 0) dataStr.Append(",");
                    dataStr.Append("\"" + dataReader[j].ToString().Replace("\"", "\\\"") + "\"");
                }
                dataStr.Append("\n");
            }

            //写文件
            StreamWriter sw = new StreamWriter(csvFile, false, Encoding.GetEncoding("utf-8"));
            sw.Write(dataStr.ToString());
            sw.Flush();
            sw.Close();

            return 1;
        }
        catch
        {
            return -1;
        }

    }

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }

}