C# Stream流方式匯入Excel,htm,txt,Doc

 /// <summary>
        /// 流方式匯出Excel
        /// </summary>
        /// <param name="dgv"></param>
        private void ExportToExcel(DataGridView dgv)
        {
            if (dgv.Rows.Count == 0)
            {
                MessageBox.Show("沒有資料可供匯出！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }
            // 儲存對話方塊
            SaveFileDialog saveFileDialog = new SaveFileDialog();
            saveFileDialog.Filter = "Execl檔案 (*.xls)|*.xls|Xml檔案 (*.xml)|*.xml|網頁檔案 (*.htm)|*.htm|網頁檔案 (*.html)|*.html|Doc檔案 (*.doc)|*.doc|文字檔 (*.txt)|*.txt|所有檔案 (*.*)|*.*";
            saveFileDialog.FilterIndex = 0;
            saveFileDialog.RestoreDirectory = true;
            saveFileDialog.CreatePrompt = true;
            saveFileDialog.Title = "匯出檔案儲存路徑";//為Excel
            saveFileDialog.FileName = null;
            saveFileDialog.ShowDialog();

            string Path = saveFileDialog.FileName;
            //被點了"取消"
            if (Path.IndexOf(":") < 0)
            {
                return;
            }

            //獲得資料類型
            string type = Path.Substring(Path.IndexOf(".") + 1);
            if (type.Equals("doc", StringComparison.CurrentCultureIgnoreCase))
            {
                //object path = Path;
                //Object none = System.Reflection.Missing.Value;
                //try
                //{
                //    Microsoft.Office.Interop.Word.Application wordApp = new Microsoft.Office.Interop.Word.Application();
                //    Microsoft.Office.Interop.Word.Document document = wordApp.Documents.Add(ref none, ref none, ref none, ref none);
                //    //建立表格
                //    Microsoft.Office.Interop.Word.Table table = document.Tables.Add(document.Paragraphs.Last.Range, dgv.Rows.Count + 1, dgv.Columns.Count, ref none, ref none);

                //    try
                //    {
                //        for (int i = 0; i < dgv.Columns.Count; i++)//設定標題
                //        {
                //            table.Cell(1, i + 1).Range.Text = dgv.Columns[i].HeaderText;
                //        }

                //        for (int i = 0; i < dgv.Rows.Count; i++)//填充資料
                //        {
                //            for (int j = 0; j < dgv.Columns.Count; j++)
                //            {
                //                table.Cell(i + 2, j + 1).Range.Text = dgv[j, i].Value.ToString();
                //            }
                //        }
                //        document.SaveAs(ref path, ref none, ref none, ref none, ref none, ref none, ref none, ref none, ref none, ref none, ref none, ref none, ref none, ref none, ref none, ref none);
                //        document.Close(ref none, ref none, ref none);
                //        MessageBox.Show("資料已經成功匯出到：" + Path, "匯出完成", MessageBoxButtons.OK, MessageBoxIcon.Information);
                //    }
                //    catch (Exception ex)
                //    {
                //        MessageBox.Show("檔案 " + Path + " 正由另一起程使用，/r/n請先關閉該進程！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                //        return;
                //    }
                //    finally
                //    {
                //        wordApp.Quit(ref none, ref none, ref none);
                //    }
                //    return;
                //}
                //catch (Exception ex)
                //{
                //    MessageBox.Show(ex.Message, "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                //    return;
                //}
            }

            Stream myStream;
            try
            {
                myStream = saveFileDialog.OpenFile();
            }
            catch (Exception ex)
            {
                MessageBox.Show("檔案 " + Path + " 正由另一起程使用，/r/n請先關閉該進程！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            StreamWriter sw = new StreamWriter(myStream, System.Text.Encoding.GetEncoding(-0));
            string columnTitle = "";

            if (type.Equals("htm", StringComparison.CurrentCultureIgnoreCase) || type.Equals("html", StringComparison.CurrentCultureIgnoreCase))
            {
                //寫入欄位標題
                columnTitle += "<table align=/"center/" border=/"1px/"><tr>";
                for (int i = 0; i < dgv.ColumnCount; i++)
                {
                    columnTitle += "<td>";
                    columnTitle += dgv.Columns[i].HeaderText + "</td>";
                }

                //寫入列內容
                for (int j = 0; j < dgv.Rows.Count; j++)
                {
                    columnTitle += "</tr><tr>";
                    for (int k = 0; k < dgv.Columns.Count; k++)
                    {
                        columnTitle += "<td>";
                        if (dgv.Rows[j].Cells[k].Value == null)
                            columnTitle += "&nbsp;</td>";
                        else
                            columnTitle += dgv.Rows[j].Cells[k].Value.ToString().Trim() + "</td>";
                    }
                }
                columnTitle += "</tr></table>";
                try
                {
                    sw.WriteLine(columnTitle);
                }
                catch
                {
                    MessageBox.Show("檔案 " + Path + " 正由另一起程使用，/r/n請先關閉該進程！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                }
                finally
                {
                    sw.Close();
                    myStream.Close();
                }
                MessageBox.Show("資料已經成功匯出到：" + Path, "匯出完成", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }

            try
            {
                //寫入欄位標題
                for (int i = 0; i < dgv.ColumnCount; i++)
                {
                    if (i > 0)
                    {
                        columnTitle += "/t";
                    }
                    columnTitle += dgv.Columns[i].HeaderText;
                }
                sw.WriteLine(columnTitle);

                //寫入列內容
                for (int j = 0; j < dgv.Rows.Count; j++)
                {
                    string columnValue = "";
                    for (int k = 0; k < dgv.Columns.Count; k++)
                    {
                        if (k > 0)
                        {
                            columnValue += "/t";
                        }
                        if (dgv.Rows[j].Cells[k].Value == null)
                            columnValue += "";
                        else
                            columnValue += dgv.Rows[j].Cells[k].Value.ToString().Trim();
                    }
                    sw.WriteLine(columnValue);
                }
                sw.Close();
                myStream.Close();
                MessageBox.Show("資料已經成功匯出到：" + Path, "匯出完成", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            catch (Exception e)
            {
                MessageBox.Show(e.ToString());
            }
            finally
            {
                sw.Close();
                myStream.Close();
            }
        }