CSV的导入导出

 using System;
 using System.Data;
 using System.IO;

 namespace COMMON
 {
     public class CSVhelperClass
     {
         /// <summary>
         /// 导出报表为Csv
         /// </summary>
         /// <param name="dt">DataTable</param>
         /// <param name="strFilePath">物理路径</param>
         /// <param name="columname">字段标题,逗号分隔</param>
         public string dt2csv(DataTable dt, string strFilePath, string columname)
         {
             try
             {
                 string strBufferLine = "";
                 StreamWriter strmWriterObj = new StreamWriter(strFilePath, false, System.Text.Encoding.UTF8);
                 strmWriterObj.WriteLine(columname);
                 for (int i = ; i < dt.Rows.Count; i++)
                 {
                     strBufferLine = "";
                     for (int j = ; j < dt.Columns.Count; j++)
                     {
                         if (j > )
                             strBufferLine += ",";
                         strBufferLine += dt.Rows[i][j].ToString();
                     }
                     strmWriterObj.WriteLine(strBufferLine);
                 }
                 strmWriterObj.Close();
                 return "备份成功";
             }
             catch (Exception ex)
             {
                 return "备份失败 " + ex.ToString();
             }
         }

         /// <summary>
         /// 将Csv读入DataTable
         /// </summary>
         /// <param name="filePath">csv文件路径</param>
         /// <param name="n">表示第n行是字段title,第n+1行是记录开始</param>
         public DataTable csv2dt(string filePath, int n, DataTable dt)
         {
             StreamReader reader = new StreamReader(filePath, System.Text.Encoding.UTF8, false);
             int i = , m = ;
             //返回下一个可用的字符
             //返回值表示下一个要读取的字符的整数，或者，如果没有更多的可用字符或该流不支持查找，则为 -1。
             reader.Peek();
             while (reader.Peek() > )
             {
                 m = m + ;
                 string str = reader.ReadLine();
                 if (m >= n + )
                 {
                     string[] lstSplit = str.Split(',');

                     System.Data.DataRow dr = dt.NewRow();
                     for (i = ; i < lstSplit.Length; i++)
                     {
                         dr[i] = lstSplit[i];
                     }
                     dt.Rows.Add(dr);
                 }
                 else
                 {
                     string[] lstTitle = str.Split(',');
                     for (i = ; i < lstTitle.Length; i++)
                     {
                         DataColumn columnItem = new DataColumn(lstTitle[i],typeof(string));
                         dt.Columns.Add(columnItem);
                     }
                 }
             }
             reader.Close();
             return dt;
         }
     }
 }