C#导出数据到CSV文件的通用类实例

//这里写了一个通用的类using System;using System.Data;using System.Configuration;using System.Collections.Generic;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using System.Text;using System.Reflection;using System.IO;using System.Data.Odbc;namespace Com.DRPENG.SDXY.UI.Common{ public class CSVHelper {  #region Fields  string _fileName;  DataTable _dataSource;//数据源  string[] _titles = null;//列标题  string[] _fields = null;//字段名  #endregion  #region .ctor  /// <summary>   /// 构造函数   /// </summary>   /// <param name="dataSource">数据源</param>   public CSVHelper()  {  }  /// <summary>   /// 构造函数   /// </summary>   /// <param name="titles">要输出到 Excel 的列标题的数组</param>   /// <param name="fields">要输出到 Excel 的字段名称数组</param>   /// <param name="dataSource">数据源</param>   public CSVHelper(string[] titles, string[] fields, DataTable dataSource)   : this(titles, dataSource)  {   if (fields == null || fields.Length == 0)    throw new ArgumentNullException("fields");   if (titles.Length != fields.Length)    throw new ArgumentException("titles.Length != fields.Length", "fields");   _fields = fields;  }  /// <summary>   /// 构造函数   /// </summary>   /// <param name="titles">要输出到 Excel 的列标题的数组</param>   /// <param name="dataSource">数据源</param>   public CSVHelper(string[] titles, DataTable dataSource)   : this(dataSource)  {   if (titles == null || titles.Length == 0)    throw new ArgumentNullException("titles");   _titles = titles;  }  /// <summary>   /// 构造函数   /// </summary>   /// <param name="dataSource">数据源</param>   public CSVHelper(DataTable dataSource)  {   if (dataSource == null)    throw new ArgumentNullException("dataSource");   // maybe more checks needed here (IEnumerable, IList, IListSource, ) ???    // 很难判断，先简单的使用 DataTable    _dataSource = dataSource;  }  #endregion  #region public Methods  #region 导出到CSV文件并且提示下载  /// <summary>  /// 导出到CSV文件并且提示下载  /// </summary>  /// <param name="fileName"></param>  public void DataToCSV(string fileName)  {   // 确保有一个合法的输出文件名    //if (fileName == null || fileName == string.Empty || !(fileName.ToLower().EndsWith(".csv")))   // fileName = GetRandomFileName();   string data = ExportCSV();   HttpContext.Current.Response.ClearHeaders();   HttpContext.Current.Response.Clear();   HttpContext.Current.Response.Expires = 0;   HttpContext.Current.Response.BufferOutput = true;   HttpContext.Current.Response.Charset = "GB2312";   HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");   HttpContext.Current.Response.AppendHeader("Content-Disposition", string.Format("attachment;filename={0}.csv", System.Web.HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8)));   HttpContext.Current.Response.ContentType = "text/h323;charset=gbk";   HttpContext.Current.Response.Write(data);   HttpContext.Current.Response.End();  }  #endregion  /// <summary>  /// 获取CSV导入的数据  /// </summary>  /// <param name="filePath">文件路径</param>  /// <param name="fileName">文件名称(.csv不用加)</param>  /// <returns></returns>  public DataTable GetCsvData(string filePath,string fileName)  {   string path = Path.Combine(filePath, fileName + ".csv");   string connString = @"Driver={Microsoft Text Driver (*.txt; *.csv)};Dbq=" + filePath + ";Extensions=asc,csv,tab,txt;";   try   {    using (OdbcConnection odbcConn = new OdbcConnection(connString))    {     odbcConn.Open();     OdbcCommand oleComm = new OdbcCommand();     oleComm.Connection = odbcConn;     oleComm.CommandText = "select * from [" + fileName + "#csv]";     OdbcDataAdapter adapter = new OdbcDataAdapter(oleComm);     DataSet ds = new DataSet();     adapter.Fill(ds, fileName);     return ds.Tables[0];     odbcConn.Close();    }    if (File.Exists(path))    {     File.Delete(path);    }   }   catch (Exception ex)   {    if (File.Exists(path))    {     File.Delete(path);    }    throw ex;   }  }  #endregion  #region 返回写入CSV的字符串  /// <summary>  /// 返回写入CSV的字符串  /// </summary>  /// <returns></returns>  private string ExportCSV()  {    if(_dataSource==null)    throw new ArgumentNullException("dataSource");   StringBuilder strbData = new StringBuilder();   if (_titles == null)   {    //添加列名    foreach (DataColumn column in _dataSource.Columns)    {     strbData.Append(column.ColumnName + ",");    }    strbData.Append("/n");    foreach (DataRow dr in _dataSource.Rows)    {     for (int i = 0; i < _dataSource.Columns.Count; i++)     {      strbData.Append(dr[i].ToString() + ",");     }     strbData.Append("/n");    }    return strbData.ToString();   }   else   {    foreach (string columnName in _titles)    {     strbData.Append(columnName + ",");    }    strbData.Append("/n");    if (_fields == null)    {     foreach (DataRow dr in _dataSource.Rows)     {      for (int i = 0; i < _dataSource.Columns.Count; i++)      {       strbData.Append(dr[i].ToString() + ",");      }      strbData.Append("/n");     }     return strbData.ToString();    }    else    {     foreach (DataRow dr in _dataSource.Rows)     {      for (int i = 0; i < _fields.Length; i++)      {       strbData.Append(_fields[i].ToString() + ",");      }      strbData.Append("/n");     }     return strbData.ToString();    }   }  }  #endregion  #region 得到一个随意的文件名  /// <summary>   /// 得到一个随意的文件名   /// </summary>   /// <returns></returns>   private string GetRandomFileName()  {   Random rnd = new Random((int)(DateTime.Now.Ticks));   string s = rnd.Next(Int32.MaxValue).ToString();   return DateTime.Now.ToShortDateString() + "_" + s + ".csv";  }  #endregion }}