.net解析Excel

/// <summary>/// /// </summary>/// <param name="filepath">文件地址</param>/// <param name="sheetName">工作博名称</param>/// <param name="x_start">从第几行开始</param>/// <param name="y_start">从第几列开始</param>/// <returns></returns>public DataTable ReaderExcel(string filepath, string sheetName, int x_start, int y_start, int x_end, int y_end){    DataTable dt = new DataTable();    using (FileStream fs = File.OpenRead(filepath))    {        IWorkbook wk;        if (Path.GetExtension(filepath) == ".xls")        {            wk = new HSSFWorkbook(fs);        }        else if (Path.GetExtension(filepath) == ".xlsx")        {            wk = new XSSFWorkbook(fs);        }        else        {            wk = null;        }        ISheet sheet = wk.GetSheet(sheetName);        for (int i = x_start; i < sheet.GetRow(y_start).LastCellNum; i++)        {            dt.Columns.Add(new DataColumn(sheet.GetRow(y_start - 1).GetCell(i).ToString())); //y_start - 1是为了读取表头        }        for (int i = y_start; i < y_end; i++)        {            DataRow row = dt.NewRow();            for (int j = 0; j < sheet.GetRow(0).LastCellNum; j++)            {                bool isDateCell = false;                try                {                    isDateCell = DateUtil.IsCellDateFormatted(sheet.GetRow(i).GetCell(j + x_start));                }                catch { }                if (isDateCell)                {                    row[j] = sheet.GetRow(i).GetCell(j + x_start).DateCellValue.ToString("yyyy/MM/dd");                }                else                {                    row[j] = sheet.GetRow(i).GetCell(j + x_start).ToString();                }            }            dt.Rows.Add(row);        }    }    return dt;}