点击按钮把datagridview中显示的数据导出到excel

新手问题，winform程序，用Linq操作的数据库，要求点击按钮把datagridview中显示的数据导出到excel，尽量详细点
public void DataToExcel(DataGridView m_DataView)
            {
                SaveFileDialog kk = new SaveFileDialog();
                kk.Title = "保存EXECL文件";
                kk.Filter = "EXECL文件(*.xls) |*.xls |所有文件(*.*) |*.*";
                kk.FilterIndex = 1;
                if (kk.ShowDialog() == DialogResult.OK)
                {
                    string FileName = kk.FileName + ".xls";
                    if (File.Exists(FileName))
                        File.Delete(FileName);
                    FileStream objFileStream;
                    StreamWriter objStreamWriter;
                    string strLine = "";
                    objFileStream = new FileStream(FileName, FileMode.OpenOrCreate, FileAccess.Write);
                    objStreamWriter = new StreamWriter(objFileStream, System.Text.Encoding.Unicode);
                    for (int i = 0; i < m_DataView.Columns.Count; i++)
                    {
                        if (m_DataView.Columns[i].Visible == true)
                        {
                            strLine = strLine + m_DataView.Columns[i].HeaderText.ToString() + Convert.ToChar(9);
                        }
                    }
                    objStreamWriter.WriteLine(strLine);
                    strLine = "";

                    for (int i = 0; i < m_DataView.Rows.Count; i++)
                    {
                        if (m_DataView.Columns[0].Visible == true)
                        {
                            if (m_DataView.Rows[i].Cells[0].Value == null)
                                strLine = strLine + " " + Convert.ToChar(9);
                            else
                                strLine = strLine + m_DataView.Rows[i].Cells[0].Value.ToString() + Convert.ToChar(9);
                        }
                        for (int j = 1; j < m_DataView.Columns.Count; j++)
                        {
                            if (m_DataView.Columns[j].Visible == true)
                            {
                                if (m_DataView.Rows[i].Cells[j].Value == null)
                                    strLine = strLine + " " + Convert.ToChar(9);
                                else
                                {
                                    string rowstr = "";
                                    rowstr = m_DataView.Rows[i].Cells[j].Value.ToString();
                                    if (rowstr.IndexOf("\r\n") > 0)
                                        rowstr = rowstr.Replace("\r\n", " ");
                                    if (rowstr.IndexOf("\t") > 0)
                                        rowstr = rowstr.Replace("\t", " ");
                                    strLine = strLine + rowstr + Convert.ToChar(9);
                                }
                            }
                        }
                        objStreamWriter.WriteLine(strLine);
                        strLine = "";
                    }
                    objStreamWriter.Close();
                    objFileStream.Close();
                    MessageBox.Show(this, "保存EXCEL成功", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
            }