Data gridvie to Execel

using System;
using System.Data;
using System.Windows.Forms;
using System.Data.SqlClient;
using Excel = Microsoft.Office.Interop.Excel;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string connectionString = "Data Source=.;Initial Catalog=pubs;Integrated Security=True";
            string sql = "SELECT * FROM Authors";
            SqlConnection connection = new SqlConnection(connectionString);
            SqlDataAdapter dataadapter = new SqlDataAdapter(sql, connection);
            DataSet ds = new DataSet();
            connection.Open();
            dataadapter.Fill(ds, "Authors_table");
            connection.Close();
            dataGridView1.DataSource = ds;
            dataGridView1.DataMember = "Authors_table";
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Excel.Application xlApp;
            Excel.Workbook xlWorkBook;
            Excel.Worksheet xlWorkSheet;
            object misValue = System.Reflection.Missing.Value;

            Int16 i, j;

            xlApp = new Excel.ApplicationClass();
            xlWorkBook = xlApp.Workbooks.Add(misValue);

            xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

            for (i = 0; i <= dataGridView1.RowCount - 2; i++)
            {
                for (j = 0; j <= dataGridView1.ColumnCount - 1; j++)
                {
                    xlWorkSheet.Cells[i + 1, j + 1] = dataGridView1[j, i].Value.ToString();
                }
            }

            xlWorkBook.SaveAs(@"c:\csharp.net-informations.xls", Excel.XlFileFormat.xlWorkbookNormal, misValue, misValue, misValue, misValue, Excel.XlSaveAsAccessMode.xlExclusive, misValue, misValue, misValue, misValue, misValue);
            xlWorkBook.Close(true, misValue, misValue);
            xlApp.Quit();

            releaseObject(xlWorkSheet);
            releaseObject(xlWorkBook);
            releaseObject(xlApp);
        }

        private void releaseObject(object obj)
        {
            try
            {
                System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
                obj = null;
            }
            catch (Exception ex)
            {
                obj = null;
                MessageBox.Show("Exception Occured while releasing object " + ex.ToString());
            }
            finally
            {
                GC.Collect();
            }
        }
    }
}

자료 출처:http://csharp.net-informations.com/datagridview/csharp-datagridview-export-excel.htm