C# csv 操作类

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

namespace YanZhiwei.DotNet2.Utilities.Common
{
    /// <summary>
    /// CSV文件转换类
    /// </summary>
    public static class CSVHelper
    {
        #region 导出到csv文件
        /// <summary>
        /// 导出到csv文件
        /// eg:
        /// CSVHelper.ToCSV(_personInfoView, @"C:UsersYanZh_000Downloadsperson.csv", "用户信息表", "名称,年龄");
        /// </summary>
        /// <param name="table">DataTable</param>
        /// <param name="filePath">导出路径</param>
        /// <param name="tableheader">标题</param>
        /// <param name="columname">列名称，以','英文逗号分隔</param>
        /// <returns>是否导出成功</returns>
        public static bool ToCSV(this DataTable table, string filePath, string tableheader, string columname)
        {
            try
            {
                if (File.Exists(filePath))
                    File.Delete(filePath);
                using (FileStream _stream = new FileStream(filePath, FileMode.Create, FileAccess.ReadWrite))
                {
                    StreamWriter _writer = new StreamWriter(_stream, Encoding.UTF8);
                    _writer.WriteLine(tableheader);
                    _writer.WriteLine(columname);
                    for (int i = 0; i < table.Rows.Count; i++)
                    {
                        for (int j = 0; j < table.Columns.Count; j++)
                        {
                            _writer.Write(table.Rows[i][j].ToString());
                            _writer.Write(",");
                        }
                        _writer.WriteLine();
                    }
                    _writer.Close();
                    return true;
                }
            }
            catch
            {
                return false;
            }
        }
        #endregion
        #region  将CSV文件导入到DataTable
        /// <summary>
        /// 将CSV文件导入到DataTable
        /// </summary>
        /// <param name="table">DataTable</param>
        /// <param name="filePath">csv文件物理路径</param>
        /// <param name="startRowIndex">数据导入起始行号</param>
        /// <returns>DataTable</returns>
        public static DataTable ImportToTable(this DataTable table, string filePath, int startRowIndex)
        {
            using (StreamReader reader = new StreamReader(filePath, Encoding.UTF8, false))
            {
                int j = 0;
                while (reader.Peek() > -1)
                {
                    j = j + 1;
                    string _line = reader.ReadLine();
                    if (j >= startRowIndex + 1)
                    {
                        string[] _dataArray = _line.Split(',');
                        DataRow _dataRow = table.NewRow();
                        for (int k = 0; k < table.Columns.Count; k++)
                        {
                            _dataRow[k] = _dataArray[k];
                        }
                        table.Rows.Add(_dataRow);
                    }
                }
                return table;
            }
        }
        #endregion
    }
}

using Microsoft.VisualStudio.TestTools.UnitTesting;
using System;
using System.Data;
using YanZhiwei.DotNet2.UtilitiesTests;
namespace YanZhiwei.DotNet2.Utilities.Common.Tests
{
    [TestClass()]
    public class CSVHelperTests
    {
        private DataTable TestTable;
        [TestMethod()]
        public void ToCSVTest()
        {
            for (Int16 i = 18; i < 28; i++)
            {
                DataRow _person = TestTable.NewRow();
                _person["Name"] = "YanZhiwei" + i;
                _person["Age"] = i;
                TestTable.Rows.Add(_person);
            }
            bool _expected = true;
            bool _actual = CSVHelper.ToCSV(TestTable, @"C:UsersYanZh_000Downloadsperson.csv", "用户信息表", "名称,年龄");
            Assert.AreEqual(_expected, _actual);
        }
        [TestInitialize]
        public void InitTestTable()
        {
            TestTable = new DataTable();
            TestTable.Columns.Add(new DataColumn("Name", typeof(string)));
            TestTable.Columns.Add(new DataColumn("Age", typeof(int)));
        }

        [TestMethod()]
        public void ImportToTableTest()
        {
            DataTable _personInfoView = TestTable.Clone();
            DataTable _expected = TestTable.Clone();
            for (Int16 i = 18; i < 28; i++)
            {
                DataRow _person = _expected.NewRow();
                _person["Name"] = "YanZhiwei" + i;
                _person["Age"] = i;
                _expected.Rows.Add(_person);
            }
            DataTable _actual = CSVHelper.ImportToTable(_personInfoView, @"C:UsersYanZh_000Downloadsperson.csv", 2);
            Assert.IsTrue(ResultSetComparer.AreIdenticalResultSets(_expected, _actual));
        }
        [TestCleanup]
        public void ResetTable()
        {
            TestTable = null;
        }
    }
}

using System.Data;
using System.IO;
 
namespace DotNet.Utilities
{
    /// <summary>
    /// CSV文件转换类
    /// </summary>
    public static class CsvHelper
    {
        /// <summary>
        /// 导出报表为Csv
        /// </summary>
        /// <param name="dt">DataTable</param>
        /// <param name="strFilePath">物理路径</param>
        /// <param name="tableheader">表头</param>
        /// <param name="columname">字段标题,逗号分隔</param>
        public static bool dt2csv(DataTable dt, string strFilePath, string tableheader, string columname)
        {
            try
            {
                string strBufferLine = "";
                StreamWriter strmWriterObj = new StreamWriter(strFilePath, false, System.Text.Encoding.UTF8);
                strmWriterObj.WriteLine(tableheader);
                strmWriterObj.WriteLine(columname);
                for (int i = 0; i < dt.Rows.Count; i++)
                {
                    strBufferLine = "";
                    for (int j = 0; j < dt.Columns.Count; j++)
                    {
                        if (j > 0)
                            strBufferLine += ",";
                        strBufferLine += dt.Rows[j].ToString();
                    }
                    strmWriterObj.WriteLine(strBufferLine);
                }
                strmWriterObj.Close();
                return true;
            }
            catch
            {
                return false;
            }
        }
 
        /// <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 static DataTable csv2dt(string filePath, int n, DataTable dt)
        {
            StreamReader reader = new StreamReader(filePath, System.Text.Encoding.UTF8, false);
            int i = 0, m = 0;
            reader.Peek();
            while (reader.Peek() > 0)
            {
                m = m + 1;
                string str = reader.ReadLine();
                if (m >= n + 1)
                {
                    string[] split = str.Split(',');
 
                    System.Data.DataRow dr = dt.NewRow();
                    for (i = 0; i < split.Length; i++)
                    {
                        dr = split;
                    }
                    dt.Rows.Add(dr);
                }
            }
            return dt;
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Text;
using System.Security.Cryptography;
using System.IO;
using System.Data;
using DEV_JIZHANG.Models;
 
namespace DEV_JIZHANG.Common
{
    public class CSVHelp
    {
 
        public char[] chSplit = new char[] { '|' };
        #region public function
        public DataTable ImportCSVToDataTable(
            string RecoveryPath,
            ref string err)
        {
            int intColCount = 0;
            bool blnFlag = true;
            DataTable mydt = new DataTable("myTableName");
            DataColumn mydc;
            DataRow mydr;
            //string   strpath   =   "test.wxt";      
            string strline;
            string[] aryline;
 
            try
            {
                System.IO.StreamReader mysr = new System.IO.StreamReader(RecoveryPath);
                while ((strline = mysr.ReadLine()) != null)
                {
                    aryline = strline.Split(chSplit);
                    if (blnFlag)
                    {
                        blnFlag = false;
                        intColCount = aryline.Length;
                        for (int i = 0; i < aryline.Length; i++)
                        {
                            mydc = new DataColumn(aryline[i]);
                            mydc.ColumnName = i.ToString();
                            mydt.Columns.Add(mydc);
                        }
                    }
                    mydr = mydt.NewRow();
                    for (int i = 0; i < intColCount; i++)
                    {
                        mydr[i] = aryline[i];
                    }
                    mydt.Rows.Add(mydr);
                }
 
                return mydt;
            }
            catch (Exception ex)
            {
                err = ex.ToString();
                return null;
            }
 
            //dgData.DataSource =mydt;    
            //dgData.DataBind(); 
        }
 
        public void DataTableToCSVFile(
            System.Data.DataTable dt,
            string BackupPath,
            string strSplitChar,
            ref string err)
        {
 
            string row;
            try
            {
                //string header;
                string tmp;
                //StreamReader sr = new StreamReader(xbkPath);
                //header = sr.ReadLine();
                //sr.Close();
                FileStream fs = File.Create(BackupPath);
                StreamWriter sw = new StreamWriter(fs);
                //sw.WriteLine(header);
 
                foreach (DataRow dr in dt.Rows)
                {
                    row = "";
                    for (int i = 0; i < dt.Columns.Count; i++)
                    {
                        if (i != dt.Columns.Count - 1)
                        {
                            tmp = dr[i].ToString().Trim().Replace(strSplitChar, "");
                            row = row + tmp + strSplitChar;
                        }
                        else
                        {
                            tmp = dr[i].ToString().Trim().Replace(strSplitChar, "");
                            row = row + tmp;
                        }
                    }
                    sw.WriteLine(row);
 
                }
                sw.Flush();
                sw.Close();
            }
            catch (Exception ex)
            {
                err = ex.ToString();
            }
        }
 
        //默认密钥向量
        public byte[] Keys = { 0xEF, 0xAB, 0x56, 0x73, 0x90, 0x32, 0xCD, 0x12 };
        ///　<summary>
        ///　DES加密字符串
        ///　</summary>
        ///　<param　name="encryptString">待加密的字符串</param>
        ///　<param　name="encryptKey">加密密钥,要求为8位</param>
        ///　<returns>加密成功返回加密后的字符串，失败返回源串</returns>
        public string EncryptDES(string encryptString, string encryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Convert.ToBase64String(mStream.ToArray());
            }
            catch
            {
                return encryptString;
            }
        }
        #endregion
    }
}

https://github.com/JoshClose/CsvHelper