nopi excel 导入

 #region 从Excel导入
        /// <summary>
        /// 读取excel ,默认第一行为标头
        /// </summary>
        /// <param name="strFileName">excel文档路径</param>
        /// <returns></returns>
        public static DataTable ExcelImport(string strFileName)
        {
            DataTable dt = new DataTable();

            ISheet sheet = null;
            using (FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read))
            {
                if (strFileName.IndexOf(".xlsx") == -1)//2003
                {
                    HSSFWorkbook hssfworkbook = new HSSFWorkbook(file);
                    sheet = hssfworkbook.GetSheetAt(0);
                }
                else//2007
                {
                    XSSFWorkbook xssfworkbook = new XSSFWorkbook(file);
                    sheet = xssfworkbook.GetSheetAt(0);
                }
            }

            System.Collections.IEnumerator rows = sheet.GetRowEnumerator();

            IRow headerRow = sheet.GetRow(0);
            int cellCount = headerRow.LastCellNum;

            for (int j = 0; j < cellCount; j++)
            {
                ICell cell = headerRow.GetCell(j);
                dt.Columns.Add(cell.ToString());
            }

            for (int i = (sheet.FirstRowNum + 1); i <= sheet.LastRowNum; i++)
            {
                IRow row = sheet.GetRow(i);
                DataRow dataRow = dt.NewRow();

                for (int j = row.FirstCellNum; j < cellCount; j++)
                {
                    if (row.GetCell(j) != null)
                        dataRow[j] = row.GetCell(j).ToString();
                }

                dt.Rows.Add(dataRow);
            }
            return dt;
        }
        #endregion

 #region RGB颜色转NPOI颜色
        private static short GetXLColour(HSSFWorkbook workbook, Color SystemColour)
        {
            short s = 0;
            HSSFPalette XlPalette = workbook.GetCustomPalette();
            NPOI.HSSF.Util.HSSFColor XlColour = XlPalette.FindColor(SystemColour.R, SystemColour.G, SystemColour.B);
            if (XlColour == null)
            {
                if (NPOI.HSSF.Record.PaletteRecord.STANDARD_PALETTE_SIZE < 255)
                {
                    XlColour = XlPalette.FindSimilarColor(SystemColour.R, SystemColour.G, SystemColour.B);
                    s = XlColour.Indexed;
                }

            }
            else
                s = XlColour.Indexed;
            return s;
        }
        #endregion

        #region 设置列的对齐方式
        /// <summary>
        /// 设置对齐方式
        /// </summary>
        /// <param name="style"></param>
        /// <returns></returns>
        private static HorizontalAlignment getAlignment(string style)
        {
            switch (style)
            {
                case "center":
                    return HorizontalAlignment.Center;
                case "left":
                    return HorizontalAlignment.Left;
                case "right":
                    return HorizontalAlignment.Right;
                case "fill":
                    return HorizontalAlignment.Fill;
                case "justify":
                    return HorizontalAlignment.Justify;
                case "centerselection":
                    return HorizontalAlignment.CenterSelection;
                case "distributed":
                    return HorizontalAlignment.Distributed;
            }
            return NPOI.SS.UserModel.HorizontalAlignment.General;


        }

        #endregion