C#在FORM页面上将excel表格从SQL数据库导出，导入txt格式表格

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Excel = Microsoft.Office.Interop.Excel;
using System.Data.SqlClient;

namespace FormPhoneWork
{
    public partial class takeinto : Form
    {
        public takeinto()
        {
            InitializeComponent();

        }

        private void openFileDialog1_FileOk(object sender, CancelEventArgs e)
        {

        }

        public int DataTabletoExcel(DataGridView tmpDataTable)
        {
            if (tmpDataTable.RowCount == 0)
                return 1;
            try
            {
                saveFileDialog1.Filter = "Execl files (*.xlsx)|*.xlsx";
                saveFileDialog1.FilterIndex = 0;
                saveFileDialog1.RestoreDirectory = true;
                saveFileDialog1.Title = "导出文件保存路径";
                saveFileDialog1.FileName = null;
                saveFileDialog1.ShowDialog();
                string FileName = saveFileDialog1.FileName;

                if (FileName != "")
                {

                    int rowNum = tmpDataTable.Rows.Count;

                    int columnNum = tmpDataTable.Columns.Count;
                    int rowIndex = 1;
                    int columnIndex = 0;

                    Excel.Application xlApp = new Excel.Application();
                    xlApp.DefaultFilePath = "";
                    xlApp.DisplayAlerts = true;
                    xlApp.SheetsInNewWorkbook = 1;
                    Excel.Workbook xlBook = xlApp.Workbooks.Add(true);

                    foreach (DataGridViewColumn dc in tmpDataTable.Columns)
                    {
                        columnIndex++;

                        xlApp.Cells[rowIndex, columnIndex] = dc.HeaderText;
                    }

                    for (int i = 0; i < rowNum; i++)
                    {

                        rowIndex++;
                        columnIndex = 0;
                        for (int j = 0; j < columnNum; j++)
                        {
                            columnIndex++;
                            xlApp.Cells[rowIndex, columnIndex] = tmpDataTable[j, i].Value;
                        }

                    }
                    xlBook.SaveCopyAs(FileName);
                    MessageBox.Show("数据已经成功导出到：" + saveFileDialog1.FileName.ToString(),
                        "导出完成", MessageBoxButtons.OK, MessageBoxIcon.Information);

                }
                return 0;
            }
            catch (System.Exception)
            {
                return 2;
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string str = "select * from " + textBox1.Text;
            string source = "server=(local);" + "integrated security=SSPI;" + "database=PhoneWork";
            SqlConnection conn = new SqlConnection(source);
            DataSet ds = new DataSet();
            SqlDataAdapter da = new SqlDataAdapter(str, source);
            da.Fill(ds, textBox1.Text);
            dataGridView1.AutoGenerateColumns = true;
            dataGridView1.DataSource = ds;
            dataGridView1.DataMember = textBox1.Text;
            DataTabletoExcel(dataGridView1);
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {

        }

        private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {

        }



        private void button2_Click(object sender, EventArgs e)
        {
            openFileDialog1.ShowDialog();
            DataExceltoTable(dataGridView1);


        }
        public void DataExceltoTable(DataGridView tmpDataTable)
        {
            string source = "server=(local);" + "integrated security=SSPI;" + "database=PhoneWork";
           // string str = "truncate table " + textBox1.Text;//清空原来的表格
            SqlConnection conn = new SqlConnection(source);
            conn.Open();
            try
            {
               // SqlCommand card = new SqlCommand(str, conn);
                //card.ExecuteNonQuery();
                SqlCommand com = new SqlCommand("BULK INSERT PhoneWork.dbo."+ textBox1.Text + " FROM '" + openFileDialog1.FileName +
                    "'WITH  (FIELDTERMINATOR = ',',ROWTERMINATOR= '\n')", conn);
                com.ExecuteNonQuery();
                MessageBox.Show("导入数据成功");

            }

            catch(Exception e)
            {
                MessageBox.Show(e.ToString());
            }
        }
    }
}