C#：将数据网格内的数据导出到Excel

public void ExportDataToExecel(DataGridView  dataGridView1)
{
    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.Trim();
                if (File.Exists(FileName))
                    File.Delete(FileName);
                System.IO.FileStream objFileStream;
                StreamWriter objStreamWriter;
                string strLine = "";
                objFileStream = new System.IO.FileStream(FileName, FileMode.OpenOrCreate, FileAccess.Write);
                objStreamWriter = new StreamWriter(objFileStream, System.Text.Encoding.Unicode);
                for (int i = 0; i < dataGridView1.Columns.Count; i++)
                {
                    if (dataGridView1.Columns[i].Visible == true)
                    {
                        strLine = strLine + dataGridView1.Columns[i].HeaderText.ToString() + Convert.ToChar(9);
                    }
                }
                objStreamWriter.WriteLine(strLine);
                strLine = "";

                for (int i = 0; i < dataGridView1.Rows.Count; i++)
                {
                    if (dataGridView1.Columns[0].Visible == true)
                    {
                        if (dataGridView1.Rows[i].Cells[0].Value == null)
                            strLine = strLine + " " + Convert.ToChar(9);
                        else
                            strLine = strLine + dataGridView1.Rows[i].Cells[0].Value.ToString() + Convert.ToChar(9);
                    }
                    for (int j = 1; j < dataGridView1.Columns.Count; j++)
                    {
                        if (dataGridView1.Columns[j].Visible == true)
                        {
                            if (dataGridView1.Rows[i].Cells[j].Value == null)
                                strLine = strLine + " " + Convert.ToChar(9);
                            else
                            {
                                string rowstr = "";
                                rowstr = dataGridView1.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);
            }

        }