csv操作帮助类

功能描述：

• 集合转换为csv数据
• DataSe转换为csv数据

  using System;
  using System.Collections.Generic;
  using System.Data;
  using System.Linq;
  using System.Text;
  
  namespace IM.Common
  {
      /// <summary>
      ///  csv操作
      /// <para>创建作者：changjin</para>
      /// <para>创建日期：2011/06/17</para>
      /// </summary>
      public class CsvHelper
      {
          public static string _seperator = ",";
          public static string _bracer = "\"";
          public static string _newline = "\n";
          public static string _regex_special = ".*[,\n\"].*";
  
          /// <summary>
          /// 集合转换为csv数据
          /// <para>创建作者：changjin</para>
          /// <para>创建日期：2011/06/17</para>
          /// </summary>
          /// <param name="list">数据集合，行、列</param>
          /// <returns>csv数据</returns>
          public static string ToCsvData(List<List<string>> list)
          {
              string temp = string.Empty;
              System.Text.StringBuilder sb = new System.Text.StringBuilder();
              foreach (List<string> row in list)
              {
                  for (int i = 0; i < row.Count; i++)
                  {
                      temp = row[i];
                      temp = (temp != null ? temp : "");
                      if (i != 0)
                      {
                          sb.Append(_seperator);
                      }
                      if (temp.Contains(_seperator) || temp.Contains(_bracer) || temp.Contains(_newline))
                      {
                          if (temp.Contains(_bracer))
                          {
                              temp = temp.Replace(_bracer, _bracer + _bracer);
                          }
                          if (temp.Contains(_newline))
                          {
                              temp = temp.Replace(_newline, "<br/>");
                          }
                          sb.Append(_bracer + temp + _bracer);
                      }
                      else
                      {
                          sb.Append(temp);
                      }
                      if (i == row.Count - 1)
                      {
                          sb.Append(_newline);
                      }
                  }
              }
              return sb.ToString();
          }
  
  
          /// <summary>
          /// DataSe转换为csv数据
          /// <para>创建作者：changjin</para>
          /// <para>创建日期：2011/06/17</para>
          /// </summary>
          /// <param name="ds">数据集</param>
          /// <returns>csv数据</returns>
          public static string ToCsvData(DataSet ds)
          {
              List<List<string>> list = new List<List<string>>();
              if (ds != null && ds.Tables.Count > 0 && ds.Tables[0] != null)
              {
                  DataTable dt = ds.Tables[0];
                  List<string> columnNameList = new List<string>();
                  //添加列
                  if (dt.Columns.Count > 0)
                  {
                      foreach (DataColumn column in dt.Columns)
                      {
                          columnNameList.Add(column.ColumnName);
                      }
                      list.Add(columnNameList);
                  }
                  //迭代添加行记录
                  foreach (DataRow row in dt.Rows)
                  {
                      List<string> rowData = new List<string>();
                      foreach (string columnName in columnNameList)
                      {
                          rowData.Add(Convert.ToString(row[columnName]));
                      }
                      list.Add(rowData);
                  }
              }
              return ToCsvData(list);
          }
      }
  }