c# 一个通过oledb读取excel,csv的类

using System;using System.Collections.Generic;using System.Text;using System.Data;using System.Data.OleDb;namespace SyncCardService{    public class ExcelReader    {        private string filePath;        private string fileName;        private OleDbConnection conn;        private DataTable readDataTable;        private string connString;        private FileType fileType = FileType.noset;        public ExcelReader()        {                    }        private void SetFileInfo(string path)        {            filePath = path;            fileName = this.filePath.Remove(0, this.filePath.LastIndexOf("\\") + 1);            switch (fileName.Split('.')[1])            {                case "xls": connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filePath + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'"; fileType = FileType.xls;                    break;                case "xlsx": connString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + filePath + ";Extended Properties='Excel 12.0;HDR=Yes;IMEX=1;'"; fileType = FileType.xlsx;                    break;                case "csv": connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filePath.Remove(filePath.LastIndexOf("\\") + 1) + ";Extended Properties='Text;FMT=Delimited;HDR=YES;'"; fileType = FileType.csv;                    break;            }        }        public DataTable ReadFile(string path)        {            if (System.IO.File.Exists(path))            {                SetFileInfo(path);                OleDbDataAdapter myCommand = null;                DataSet ds = null;                using (conn = new OleDbConnection(connString))                {                    conn.Open();                    DataTable schemaTable = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);                    string tableName = fileType == FileType.csv ? fileName : schemaTable.Rows[0][2].ToString().Trim();                    string strExcel = string.Empty;                    strExcel = "Select   *   From   [" + tableName + "]";                    myCommand = new OleDbDataAdapter(strExcel, conn);                    ds = new DataSet();                    myCommand.Fill(ds, tableName);                    readDataTable = ds.Tables[0];                }            }            return readDataTable;        }        private enum FileType        {            noset,            xls,            xlsx,            csv        }    }}