csv 格式文件 导入导出

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.Common;
using System.Data.OleDb;
using System.IO;

/// <summary>
/// DataSet2CSV 的摘要说明
/// </summary>
public class DataSet2CSV
{
    public DataSet2CSV()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }
    #region 001----将DataSet转换成CSV文件
    public static void Export2CSV(DataSet ds, string tableName, bool containColumName, string fileName)
    {
        string csvStr = ConverDataSet2CSV(ds, tableName, containColumName);
        if (csvStr == "") return;
        FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.ReadWrite);
        //将string转换成byte[]
        byte[] csvArray = System.Text.Encoding.ASCII.GetBytes(csvStr.ToCharArray(), 0, csvStr.Length - 1);
        fs.Write(csvArray, 0, csvStr.Length - 1);
        fs.Close();
        fs = null;
    }

    /// <summary>
    /// 将指定的数据集中指定的表转换成CSV字符串
    /// </summary>
    /// <param name="ds"></param>
    /// <param name="tableName"></param>
    /// <returns></returns>
    public static string ConverDataSet2CSV(DataSet ds, string tableName, bool containColumName)
    {
        //首先判断数据集中是否包含指定的表
        if (ds == null || (!ds.Tables.Contains(tableName) && ds.Tables.Count < int.Parse(tableName)))
        {
            //MessageBox.Show("指定的数据集为空或不包含要写出的数据表！", "系统提示：", MessageBoxButtons.OK, MessageBoxIcon.Stop);

            return "";
        }
        string csvStr = "";
        //下面写出数据
        DataTable tb = !ds.Tables.Contains(tableName) ? ds.Tables[int.Parse(tableName)]: ds.Tables[tableName];
        //写表名
        //csvStr += tb.TableName + "\n";
        //第一步：写出列名
        if (containColumName)
        {
            foreach (DataColumn column in tb.Columns)
            {
                csvStr += "\"" + column.ColumnName + "\"" + ",";
            }
            //去掉最后一个","
            csvStr = csvStr.Remove(csvStr.LastIndexOf(","), 1);
            csvStr += "\n";
        }
        //第二步：写出数据
        foreach (DataRow row in tb.Rows)
        {
            foreach (DataColumn column in tb.Columns)
            {
                csvStr += "\"" + row[column].ToString() + "\"" + ",";
            }
            csvStr = csvStr.Remove(csvStr.LastIndexOf(","), 1);
            csvStr += "\n";
        }
        return csvStr;
    }

    #endregion

    #region 002----从CSV文件填充DataSet
    public static DataSet ConverCSV2DataSet(string fileName, string tableName, int StartSN, int EndSN)
    {
        DataSet ds = new DataSet();
        string _filePath, _fileName;
        _filePath = fileName.Substring(0, fileName.LastIndexOf(@"\") + 1);
        _fileName = fileName.Substring(fileName.LastIndexOf(@"\") + 1);
        string conStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= " + _filePath + @"\" + ";Extended Properties=\"Text;HDR=Yes;FMT=Delimited\"";
        OleDbConnection oleCon = new OleDbConnection(conStr);
        OleDbDataAdapter da = new OleDbDataAdapter("Select * from " + _fileName + " where cint(one) >=" + StartSN + " and cint(one) <=" + EndSN, oleCon);
        da.Fill(ds, tableName);
        oleCon.Close();
        return ds;
    }
    #endregion
}