读写CSV到DataTable

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.OleDb;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SanJuSFTP
{
    public class Common
    {

        public static DataTable CsvToDt(string path)
        {
            OleDbConnection OleCon = new OleDbConnection();
            try
            {
                DataSet dsCsvData = new DataSet();
                OleDbCommand OleCmd = new OleDbCommand();
                OleDbDataAdapter OleDa = new OleDbDataAdapter();

                OleCon.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path.Substring(0, path.LastIndexOf("\")) + ";Extended Properties='Text;FMT=Delimited(,);HDR=YES;IMEX=1';";

                OleCon.Open();

                OleCmd.Connection = OleCon;
                OleCmd.CommandText = "select * from [" + path.Substring(path.LastIndexOf("\") + 1) + "] where 1=1";
                OleDa.SelectCommand = OleCmd;
                OleDa.Fill(dsCsvData, "Csv");
                return dsCsvData.Tables[0];
            }
            catch (Exception ex)
            {
                LogHelper.WriteLog(ex.Message);
                return null;
            }
            finally
            {
                OleCon.Close();
            }
        }


        /// <summary>
        /// datatable转csv
        /// </summary>
        /// <param name="dt"></param>
        /// <param name="fileName"></param>
        public static void DtToCsv(DataTable dt, string fileName)
        {
            FileStream fs = new FileStream(fileName, System.IO.FileMode.Create, System.IO.FileAccess.Write);
            StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.Default);
            try
            {
                string data = "";

                //写出列名称
                for (int i = 0; i < dt.Columns.Count; i++)
                {
                    data += dt.Columns[i].ColumnName.ToString();
                    if (i < dt.Columns.Count - 1)
                    {
                        data += ",";
                    }
                }
                sw.WriteLine(data);

                //写出各行数据
                for (int i = 0; i < dt.Rows.Count; i++)
                {
                    data = "";
                    for (int j = 0; j < dt.Columns.Count; j++)
                    {
                        data += "" + dt.Rows[i][j].ToString();
                        if (j < dt.Columns.Count - 1)
                        {
                            data += ",";
                        }
                    }
                    sw.WriteLine(data);
                }
            }
            catch (Exception ex)
            {
            }
            finally
            {
                sw.Close();
                fs.Close();
            }

        }

        /// <summary>
        /// 新文件名
        /// </summary>
        /// <param name="oldFilePath">文件路径</param>
        /// <param name="oldFileName">文件名称</param>
        /// <returns></returns>
        public static string GetNewFilePath(string oldFilePath, string oldFileName)
        {
            string newFilePath = oldFilePath + oldFileName.Substring(0, oldFileName.IndexOf("."))
                + DateTime.UtcNow.ToString("yyyyMMdd") +
                oldFileName.Substring(oldFileName.IndexOf("."));
            return newFilePath;
        }


        /// <summary>
        /// 修改本地文件名
        /// </summary>
        /// <param name="oldStr">旧文件名</param>
        /// <param name="newStr">新文件名</param>
        public static void Rename_Local(string oldStr, string newStr)
        {
            // 改名方法
            FileInfo fi = new FileInfo(oldStr);
            FileInfo fi_new = new FileInfo(newStr);
            if (fi_new.Exists)
            {
                fi_new.Delete();
            }
            fi.MoveTo(Path.Combine(newStr));
        }
    }
}