CSV的导入导出

 1 using System;
 2 using System.Data;
 3 using System.IO;
 4 
 5 namespace COMMON
 6 {
 7     public class CSVhelperClass
 8     {
 9         /// <summary>  
10         /// 导出报表为Csv  
11         /// </summary>  
12         /// <param name="dt">DataTable</param>  
13         /// <param name="strFilePath">物理路径</param>          
14         /// <param name="columname">字段标题,逗号分隔</param>  
15         public string dt2csv(DataTable dt, string strFilePath, string columname)
16         {
17             try
18             {
19                 string strBufferLine = "";
20                 StreamWriter strmWriterObj = new StreamWriter(strFilePath, false, System.Text.Encoding.UTF8);                 
21                 strmWriterObj.WriteLine(columname);
22                 for (int i = 0; i < dt.Rows.Count; i++)
23                 {
24                     strBufferLine = "";
25                     for (int j = 0; j < dt.Columns.Count; j++)
26                     {
27                         if (j > 0)
28                             strBufferLine += ",";
29                         strBufferLine += dt.Rows[i][j].ToString();
30                     }
31                     strmWriterObj.WriteLine(strBufferLine);
32                 }
33                 strmWriterObj.Close();
34                 return "备份成功";
35             }
36             catch (Exception ex)
37             {
38                 return "备份失败 " + ex.ToString();
39             }
40         }
41 
42         /// <summary>  
43         /// 将Csv读入DataTable  
44         /// </summary>  
45         /// <param name="filePath">csv文件路径</param>  
46         /// <param name="n">表示第n行是字段title,第n+1行是记录开始</param>  
47         public DataTable csv2dt(string filePath, int n, DataTable dt)
48         {
49             StreamReader reader = new StreamReader(filePath, System.Text.Encoding.UTF8, false);
50             int i = 0, m = 0;
51             //返回下一个可用的字符
52             //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。
53             reader.Peek();
54             while (reader.Peek() > 0)
55             {
56                 m = m + 1;
57                 string str = reader.ReadLine();
58                 if (m >= n + 1)
59                 {
60                     string[] lstSplit = str.Split(',');
61 
62                     System.Data.DataRow dr = dt.NewRow();
63                     for (i = 0; i < lstSplit.Length; i++)
64                     {
65                         dr[i] = lstSplit[i];
66                     }
67                     dt.Rows.Add(dr);
68                 }
69                 else
70                 {
71                     string[] lstTitle = str.Split(',');
72                     for (i = 0; i < lstTitle.Length; i++)
73                     {
74                         DataColumn columnItem = new DataColumn(lstTitle[i],typeof(string));
75                         dt.Columns.Add(columnItem);
76                     }
77                 }
78             }
79             reader.Close();
80             return dt;
81         } 
82     }
83 }