NPOI 导出Excel部分

  if (this.testDataSet1.TestTable.Rows.Count <= 0)
            {
                MessageBox.Show("没有找到相关的数据！", "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }
            DialogResult isOK = new DialogResult();
            IWorkbook workbook = null;
            ISheet sheet = null;

            //导出文件对话框
            SaveFileDialog saveFile = new SaveFileDialog();
            saveFile.Filter = "Excel 2003兼容格式|*.xls|Excel 2007文件格式|*.xlsx";    //设置文件过滤器
            saveFile.FileName = dateTimePicker2.Value.ToString("yyyy-MM-dd") + "至" + dateTimePicker3.Value.ToString("yyyy-MM-dd") + "统计表";
            isOK = saveFile.ShowDialog();
            if (isOK != DialogResult.OK  || String.IsNullOrEmpty(saveFile.FileName))
            {
                return;
            }
            else
            {
                try
                {
                    int rowIndex = 0;     //行号
                    workbook = CreateIWorkBook(@saveFile.FileName.ToString());     //创建Excel                     
                    FileStream fs = new FileStream(saveFile.FileName, FileMode.OpenOrCreate);        //创建文件流打开或创建
                    sheet = workbook.CreateSheet("Sheet1");     //创建sheet 
                    IRow row = null;
                    ICell cell = null;
                    //从数据集中读数据
                    int rowCount = testDataSet1.TestTable.Rows.Count;    //rowCount 行数
                    int colCount = 11;//colCount 列数
                    //创建表头
                    string[] header = { "单号", "名称", "日期", "金额", "实付金额", "销款金额", "付款方式", "银行", "单据类型", "单据号码", "备注" };     //列名
                    string[] col = { "DanHao", "MingCheng", "RiQi", "JinE", "ShiFu", "XiaoKuan", "FangShi", "YinHang", "LeiXing", "DanJuHao", "BeiZhu" };      //数据集列
                    row = sheet.CreateRow(rowIndex);
                    cell = row.CreateCell(0);
                    cell.SetCellValue("Excel文件名");
                    row = sheet.CreateRow(++rowIndex);    //rowIndex = 1;
                    //输出列名
                    for (int colIndex = 0; colIndex < colCount; ++colIndex)
                    {
                        cell = row.CreateCell(colIndex);
                        cell.SetCellValue(header[colIndex]);
                    }
                    //int rowIndex = 2;
                    foreach (DataRow dr in testDataSet1.TestTable.Rows)
                    // for (; rowIndex < rowCount+2;++rowIndex  )
                    {
                        row = sheet.CreateRow(++rowIndex);
                        for (int colIndex = 0; colIndex < 11; ++colIndex)
                        {
                            cell = row.CreateCell(colIndex);
                            //cell.SetCellValue(testDataSet1.TestTable[rowIndex-2][col[colIndex]].ToString());     
                            if (dr[col[colIndex]].GetType().Equals(typeof(System.DateTime)))     //日期格式
                            {
                                cell.SetCellValue(Convert.ToDateTime(dr[col[colIndex]]).ToString("yyyy-MM-dd"));
                            }
                            else if (dr[col[colIndex]].GetType().Equals(typeof(System.Double)))      //Double
                            {
                                cell.SetCellValue(Convert.ToDouble(dr[col[colIndex]]));
                            }
                            else if (dr[col[colIndex]].GetType().Equals(typeof(System.Int32)))     //Int
                            {
                                cell.SetCellValue(Convert.ToInt32(dr[col[colIndex]]));      
                            }
                            else
                            {
                                cell.SetCellValue(dr[col[colIndex]].ToString().Trim());
                            }
                        }
                        //++rowIndex;
                    }
                    workbook.Write(fs);     //写入文件流
                    fs.Close();       //关闭文件流
                    MessageBox.Show("文件 '" + saveFile.FileName + "' 保存成功！");
                }   
             catch (Exception ex) { MessageBox.Show(ex.Message); }
            }