使用兩種方式實現的excel數據轉化成DataSet，再結合前一篇的DataTable轉化為實體，就可以解決excel到實體之間的轉化。

代碼如下：

首先定義一個接口：

    public interface IExcelAccess
    {
        DataSet Load(ExcelConfig config);
    }

public class ExcelConfig
    {
        /// <summary>
        /// 文件存儲路徑
        /// </summary>
        public
 
 string Path { get; set; }

        /// <summary>
        /// 文件表頭所在行索引
        /// </summary>
        public int HeaderIndex { get; set; }
    }

再來看一下使用NPOI的實現：

public class NpoiExcelAccess : IExcelAccess
    {
        /// <summary>
        /// 根據文件擴展名，獲取workbook實例
        /// </summary>
 

        /// <param name="ext"></param>
        /// <returns></returns>
        private IWorkbook GetWorkBook(string ext, Stream stream)
        {
            IWorkbook workbook = null;

            switch (ext)
            {
                case ".xlsx":
                    workbook 
 
= new XSSFWorkbook(stream);
                    break;
                case ".xls":
                    workbook = new HSSFWorkbook(stream);
                    break;
                default:
                    break;
            }

            return workbook;
        }

        /// <summary>
        /// 加載數據，可設置跳過前幾行
        /// </summary>
        /// <param name="path"></param>
        /// <param name="skipRows"></param>
        /// <returns></returns>
        public DataSet Load(ExcelConfig config)
        {
            using (var fileStream = new FileStream(config.Path, FileMode.Open, FileAccess.Read))
            {
                var ds = new DataSet();
                var ext = Path.GetExtension(config.Path);

                // 新建IWorkbook對象 
                var workbook = this.GetWorkBook(ext, fileStream);

                for (int i = 0; i < workbook.NumberOfSheets; i++)
                {
                    ISheet sheet = workbook.GetSheetAt(i);
                    DataTable dt = GetDataTable(sheet, config.HeaderIndex);
                    ds.Tables.Add(dt);
                }

                return ds;
            }
        }

        private DataTable GetDataTable(ISheet sheet, int headerIndex)
        {
            var dt = new DataTable();
            // 獲取表頭行
            var headerRow = sheet.GetRow(headerIndex);
            var cellCount = GetCellCount(sheet, headerIndex);

            // 設置表頭
            for (int i = 0; i < cellCount; i++)
            {
                if (headerRow.GetCell(i) != null)
                {
                    dt.Columns.Add(headerRow.GetCell(i).StringCellValue, typeof(string));
                }
            }
            
            for (int i = headerIndex + 1; i <= sheet.LastRowNum; i++)
            {
                IRow row = sheet.GetRow(i);
                DataRow dr = dt.NewRow();
                FillDataRow(row, ref dr);
                dt.Rows.Add(dr);
            }

            dt.TableName = sheet.SheetName;
            return dt;

        }

        private void FillDataRow(IRow row, ref DataRow dr)
        {
            if (row != null)
            {
                for (int j = 0; j < dr.Table.Columns.Count; j++)
                {
                    ICell cell = row.GetCell(j);

                    if (cell != null)
                    {
                        switch (cell.CellType)
                        {
                            case CellType.Blank:
                                dr[j] = DBNull.Value;
                                break;
                            case CellType.Boolean:
                                dr[j] = cell.BooleanCellValue;
                                break;
                            case CellType.Numeric:
                                if (DateUtil.IsCellDateFormatted(cell))
                                {
                                    dr[j] = cell.DateCellValue;
                                }
                                else
                                {
                                    dr[j] = cell.NumericCellValue;
                                }
                                break;
                            case CellType.String:
                                dr[j] = cell.StringCellValue;
                                break;
                            case CellType.Error:
                                dr[j] = cell.ErrorCellValue;
                                break;
                            case CellType.Formula:
                                // cell = evaluator.EvaluateInCell(cell) as HSSFCell;
                                dr[j] = cell.ToString();
                                break;
                            default:
                                throw new NotSupportedException(string.Format("Catched unhandle CellType[{0}]", cell.CellType));
                        }
                    }
                }
            }
        }

        /// <summary>
        /// 獲取表頭列數
        /// </summary>
        /// <param name="sheet"></param>
        /// <param name="skipRows"></param>
        /// <returns></returns>
        private int GetCellCount(ISheet sheet, int headerIndex)
        {
            var headerRow = sheet.GetRow(headerIndex);

            return headerRow.LastCellNum;
        }
    }

最後看一下使用OLEDB的實現，這裏，我只實現了excel2003的版本，07版本的總是失敗，查了原因，是需要在本機安裝一個組件才能支持導入.xlsx文件。

 public class OleDbExcelAccess : IExcelAccess
    {
        private string strConn;

        public OleDbExcelAccess()
        {
            //TODO 需要根據擴展名，來決定 使用哪一種連接字符串
            strConn = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = {0};Extended Properties=‘Excel 8.0;IMEX=1;HDR=NO‘";
        }

        public DataSet Load(ExcelConfig config)
        {
            var ds = new DataSet();
            var sheets = GetSheetNames(config.Path);
            var strConnTmp = string.Format(strConn, config.Path);

            foreach (string sheet in sheets)
            {
                using (var oleConn = new OleDbConnection(strConnTmp))
                {
                    var strsql = "SELECT * FROM [" + sheet + "]";
                    var oleDaExcel = new OleDbDataAdapter(strsql, oleConn);
                    oleConn.Open();
                    oleDaExcel.Fill(ds, sheet);
                }
            }

            return ds;
        }

        /// <summary>
        /// 獲取Excel的所有的sheet
        /// </summary>
        /// <param name="path"></param>
        /// <returns></returns>
        private string[] GetSheetNames(string path)
        {
            DataTable dt = new DataTable();
            if (File.Exists(path))
            {
                string strConnTmp = string.Format(strConn, path);
                using (var conn = new OleDbConnection(strConnTmp))
                {
                    conn.Open();
                    //返回Excel的架構，包括各個sheet表的名稱,類型，創建時間和修改時間等    
                    dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "Table" });
                }
                //包含excel中表名的字符串數組
                var sheetNames = new List<string>();
                for (int k = 0; k < dt.Rows.Count; k++)
                {
                    string tableName = dt.Rows[k]["TABLE_NAME"].ToString();
                    //修正出現兼容性視圖名稱時過濾表名
                    if (!tableName.Substring(tableName.Length - 1).Equals("_"))
                    {
                        sheetNames.Add(tableName);
                    }
                }
                return sheetNames.ToArray();

            }
            return null;

        }
    }

最後看一下客戶端的調用 ：

 private void TestExcelImport()
        {
            var excelFile = Path.Combine("C:\\Users\\hankk\\Desktop\\ICON", "2003版本.xls");

            ExcelConfig config = new ExcelConfig()
            {
                Path = excelFile,
                HeaderIndex = 1
            };

            IExcelAccess npoiAccess = new NpoiExcelAccess();
            var npoiDs = npoiAccess.Load(config);

            IExcelAccess oleDbAccess = new OleDbExcelAccess();
            var oleDs = oleDbAccess.Load(config);
        }

代碼已上傳到github: https://github.com/hankuikuide/ExcelAccessor

Excel轉化成DataTable實現：NPOI和OLEDb