winfrom大数据导入excel

最近由于项目的需要 需要从excel里面导入大量数据   网上找了很久  都没有找到一个好的方法  直到。。。。。。。。  不多说  直接上代码

using System.Collections.Generic;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System.IO;
using System.Data;
using System;

     private void button10_Click(object sender, EventArgs e)
        {
            npoiWorkBook = null;
            OpenFileDialog file = new OpenFileDialog();
            if (file.ShowDialog() == DialogResult.OK)
            {
                string filePath = file.FileName;
                FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
                StreamReader sr = new StreamReader(fs);
                if (filePath.Contains(".xlsx"))
                    npoiWorkBook = new XSSFWorkbook(fs);
                else
                    npoiWorkBook = new HSSFWorkbook(fs);
            }
            else { return; }
            ExcelHelper excel = new ExcelHelper(npoiWorkBook);
//遍历第几个sheet（2就表示遍历sheet1 ，1就表示从第一行开始）
            DataTable dataTable = excel.ExportExcelToDataTable(2, 1);
            int rowCount = dataTable.Rows.Count;//总行数 
            Thread td = new Thread(new ThreadStart(delegate
            {
                foreach (DataRow row in dataTable.Rows)
                {
                    using (NewContext context = new NewContext())
                    {
                        try
                        {
                            string stationCode = row["站址编码"].ToString();
                            if (string.IsNullOrWhiteSpace(stationCode))
                                continue;
                            var station = context.Station.FirstOrDefault(o => o.StationCode == stationCode);
                            if (station == null)
                            {
                                station = new Station()
                                {
                                    BuildType = GetBType(row["xxxx"].ToString()),
                                    City = "xxxx",
                                    County = row["所属区域"].ToString().Trim(),
                                    CreateTime = DateTime.Now,
                                    CrmOrderCode = "未知",
                                    MobileIsShare = row["xxxx"].ToString().Contains("xx"),
                                    UnicomIsShare = row["xxxx"].ToString().Contains("xx"),
                                    TelecomIsShare = row["xxxx"].ToString().Contains("xx"),
                                    PROperator = GetPR(row["xxxx"].ToString()),
                                    Remark = "",
                                    ShareType = row["xxxx"].ToString().Contains("x") ? 1 : 2,
                                    StationCode = row["xxxx"].ToString(),
                                    StationName = row["xxxx"].ToString(),

                                };
                                context.Station.Add(station);
                            }
                        }
                        catch (Exception)
                        {

                            throw;
                        }
                        context.SaveChanges();
                    }
                }


            }));

            td.Start();


        }

       
//查询遍历第几个sheet  返回DataTable

public DataTable ExportExcelToDataTable(int sheetIndex, int satartNum)
        {
            return ExportToDataTable(_IWorkbook.GetSheetAt(sheetIndex - 1), satartNum);
        }