C#把DataTable导出为Excel文件

/// <summary>
/// DataTable数据导出Excel
/// </summary>
/// <param name="data"></param>
/// <param name="filepath"></param>
public static void DataTableExport(DataTable data, string filepath)
{
    try
    {
        //Workbook book = new Workbook("E:\\test.xlsx"); //打开工作簿
        Workbook book = new Workbook(); //创建工作簿
        Worksheet sheet = book.Worksheets[0]; //创建工作表
        Cells cells = sheet.Cells; //单元格
        //创建样式
        Aspose.Cells.Style style = book.Styles[book.Styles.Add()];
        style.Borders[Aspose.Cells.BorderType.LeftBorder].LineStyle = Aspose.Cells.CellBorderType.Thin; //应用边界线 左边界线  
        style.Borders[Aspose.Cells.BorderType.RightBorder].LineStyle = Aspose.Cells.CellBorderType.Thin; //应用边界线 右边界线  
        style.Borders[Aspose.Cells.BorderType.TopBorder].LineStyle = Aspose.Cells.CellBorderType.Thin; //应用边界线 上边界线  
        style.Borders[Aspose.Cells.BorderType.BottomBorder].LineStyle = Aspose.Cells.CellBorderType.Thin; //应用边界线 下边界线   
        style.HorizontalAlignment = TextAlignmentType.Center; //单元格内容的水平对齐方式文字居中
        style.Font.Name = "宋体"; //字体
        style1.Font.IsBold = true; //设置粗体
        style.Font.Size = 11; //设置字体大小
        //style.ForegroundColor = System.Drawing.Color.FromArgb(153, 204, 0); //背景色
        //style.Pattern = Aspose.Cells.BackgroundType.Solid; //背景样式
        //style.IsTextWrapped = true; //单元格内容自动换行
        
        //表格填充数据
        int Colnum = data.Columns.Count;//表格列数 
        int Rownum = data.Rows.Count;//表格行数 
        //生成行 列名行 
        for (int i = 0; i < Colnum; i++)
        {
            cells[0, i].PutValue(data.Columns[i].ColumnName); //添加表头
            cells[0, i].SetStyle(style); //添加样式
            //cells.SetColumnWidth(i, data.Columns[i].ColumnName.Length * 2 + 1.5); //自定义列宽
            //cells.SetRowHeight(0, 30); //自定义高
        }
        //生成数据行 
        for (int i = 0; i < Rownum; i++)
        {
            for (int k = 0; k < Colnum; k++)
            {
                cells[1 + i, k].PutValue(data.Rows[i][k].ToString()); //添加数据
                cells[1 + i, k].SetStyle(style); //添加样式
            }
            cells[1 + i, 5].Formula = "=B" + (2 + i) + "+C" + (2 + i);//给单元格设置计算公式，计算班级总人数
        }
        sheet.AutoFitColumns(); //自适应宽
        book.Save(filepath); //保存
        GC.Collect();
    }
    catch (Exception e)
    {
        logger.Error("生成excel出错：" + e.Message);
    }
}

public void ToExcel(DataTable dt)
    {
        #region 3s  
        var FilePath = @"D:\ToExcel\";//产生Excel文件路径
        DeleteFile(FilePath);
        //创建全新的Workbook 
        var workbook = new HSSFWorkbook();//一個sheet最多65536行
        var count = 0;
        for (double i = 0; i < Convert.ToDouble(dt.Rows.Count) / Convert.ToDouble(65534); i++)//每个Excel文件的一个页签只能存放65536行数据
        {
            var row_index = 0;
            //创建Sheet
            workbook.CreateSheet("Sheet" + i);
            //根据Sheet名字获得Sheet对象  
            var sheet = workbook.GetSheet("Sheet" + i);
            IRow row;
            row = sheet.CreateRow(row_index);

            //写入标题
            for (int j = 0; j < dt.Columns.Count; j++)
            {
                row.CreateCell(j).SetCellValue(dt.Columns[j].Caption.ToString());
            }
            row = sheet.CreateRow(++row_index);

            //写入数据
            for (int j = 0; j < (dt.Rows.Count - count > 65534 ? 65534 : dt.Rows.Count - count); j++)
            {
                var r = dt.Rows[j + count];
                for (int k = 0; k <dt.Columns.Count; k++)
                {
                    row.CreateCell(k).SetCellValue(r[k].ToString());

                    //如果是数字,判断是否需要转换为数字
                    //if (IsNumeric(r[k].ToString()))
                    //{
                    //    row.CreateCell(k).SetCellValue(Convert.ToDouble(r[k].ToString()));
                    /