在c＃中动态地向datatable添加新数据行

Question

我正在做一个从 Excel 表读取数据并将其写入另一个 Excel 表的应用程序。我使用卷号作为我的搜索键值从源 Excel 表中检索值。

我的问题是，当存在单个卷号时，将检索值。我想检索多个卷号的数据。我怎么能做到这一点？我使用DataTable来存储我检索到的值。

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.OleDb;

namespace new1
{
    public partial class Form1 : Form
    {
        static OleDbConnection oldb = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\\sample.xlsx;Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\";"); 
        OleDbCommand olc;
        string fn;
        OleDbDataAdapter adb = new OleDbDataAdapter();
        System.Data.DataTable dt = new System.Data.DataTable();

        String cmd= "Select ";
        int i = 0;
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        { 


            oldb = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\\sample.xlsx;Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\";");
            oldb.Open();
            Excel.Application app = new Excel.Application();
            app.Workbooks.Add();
           Excel._Worksheet ws = app.ActiveSheet;





                cmd += "* from [Sheet1$] where [Roll NUmber]="+textBox1.Text ;


                    olc = new OleDbCommand(cmd, oldb);
                    olc.ExecuteNonQuery();
                    adb.SelectCommand = olc;

                    adb.Fill(dt);

                                    for (int i = 0; i < (dt.Rows.Count) - 1; i++)
                {
                    for (int j = 0; j < dt.Columns.Count; j++)
                    {
                        ws.Cells[1, (j + 1)] = dt.Rows[i][j];

                    }
                }


                        SaveFileDialog sfd = new SaveFileDialog();
            sfd.DefaultExt = "Excel Files|*.xlsx;*.xlsx";
            sfd.Filter = "Excel Files|*.xlsx;*.xlsx";

            if (sfd.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                try
                {
                    ws.SaveAs(sfd.FileName );
                    app.Quit();
                }
                catch (Exception ex)
                {
                    MessageBox.Show("Problem" + ex.Message);
                }
            }

            oldb.Close();


        }