NPOI读写Excel （使用NPOI2.0 包含03和07版本）

NPOI 2.0将OOXML的代码放在了单独的DLL中，使用前请确保引用了以下DLL

NPOI.dll

NPOI.OOXML.dll

NPOI.OpenXml4Net.dll

NPOI.OpenXmlFormats.dll

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感谢原博主的整理，可以直接用。以下转自http://www.cnblogs.com/luxiaoxun/p/3374992.html

1、整个Excel表格叫做工作表：WorkBook（工作薄），包含的叫页（工作表）：Sheet；行：Row；单元格Cell。

2、NPOI是POI的C#版本，NPOI的行和列的index都是从0开始

3、POI读取Excel有两种格式一个是HSSF，另一个是XSSF。 HSSF和XSSF的区别如下：
HSSF is the POI Project's pure Java implementation of the Excel '97(-2007) file format.
XSSF is the POI Project's pure Java implementation of the Excel 2007 OOXML (.xlsx) file format.
即：HSSF适用2007以前的版本,XSSF适用2007版本及其以上的。

下面是用NPOI读写Excel的例子：ExcelHelper封装的功能主要是把DataTable中数据写入到Excel中，或者是从Excel读取数据到一个DataTable中。

 ExcelHelper类：

using System;using System.Collections.Generic;using System.Linq;using System.Text;using NPOI.SS.UserModel;using NPOI.XSSF.UserModel;using NPOI.HSSF.UserModel;using System.IO;using System.Data;namespace GMapDemo{    class ExcelHelper : IDisposable    {        private string fileName = null; //文件名        private IWorkbook workbook = null;        private FileStream fs = null;        private bool disposed;        public ExcelHelper(string fileName)        {            this.fileName = fileName;            disposed = false;        }        /// <summary>        /// 将DataTable数据导入到excel中        /// </summary>        /// <param name="data">要导入的数据</param>        /// <param name="isColumnWritten">DataTable的列名是否要导入</param>        /// <param name="sheetName">要导入的excel的sheet的名称</param>        /// <returns>导入数据行数(包含列名那一行)</returns>        public int DataTableToExcel(DataTable data, string sheetName, bool isColumnWritten)        {            int i = 0;            int j = 0;            int count = 0;            ISheet sheet = null;            fs = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);            if (fileName.IndexOf(".xlsx") > 0) // 2007版本                workbook = new XSSFWorkbook();            else if (fileName.IndexOf(".xls") > 0) // 2003版本                workbook = new HSSFWorkbook();            try            {                if (workbook != null)                {                    sheet = workbook.CreateSheet(sheetName);                }                else                {                    return -1;                }                if (isColumnWritten == true) //写入DataTable的列名                {                    IRow row = sheet.CreateRow(0);                    for (j = 0; j < data.Columns.Count; ++j)                    {                        row.CreateCell(j).SetCellValue(data.Columns[j].ColumnName);                    }                    count = 1;                }                else                {                    count = 0;                }                for (i = 0; i < data.Rows.Count; ++i)                {                    IRow row = sheet.CreateRow(count);                    for (j = 0; j < data.Columns.Count; ++j)                    {                        row.CreateCell(j).SetCellValue(data.Rows[i][j].ToString());                    }                    ++count;                }                workbook.Write(fs); //写入到excel                return count;            }            catch (Exception ex)            {                Console.WriteLine("Exception: " + ex.Message);                return -1;            }        }        /// <summary>        /// 将excel中的数据导入到DataTable中        /// </summary>        /// <param name="sheetName">excel工作薄sheet的名称</param>        /// <param name="isFirstRowColumn">第一行是否是DataTable的列名</param>        /// <returns>返回的DataTable</returns>        public DataTable ExcelToDataTable(string sheetName, bool isFirstRowColumn)        {            ISheet sheet = null;            DataTable data = new DataTable();            int startRow = 0;            try            {                fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);                if (fileName.IndexOf(".xlsx") > 0) // 2007版本                    workbook = new XSSFWorkbook(fs);                else if (fileName.IndexOf(".xls") > 0) // 2003版本                    workbook = new HSSFWorkbook(fs);                if (sheetName != null)                {                    sheet = workbook.GetSheet(sheetName);                }                else                {                    sheet = workbook.GetSheetAt(0);                }                if (sheet != null)                {                    IRow firstRow = sheet.GetRow(0);                    int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数                    if (isFirstRowColumn)                    {                        for (int i = firstRow.FirstCellNum; i < cellCount; ++i)                        {                            DataColumn column = new DataColumn(firstRow.GetCell(i).StringCellValue);                            data.Columns.Add(column);                        }                        startRow = sheet.FirstRowNum + 1;                    }                    else                    {                        startRow = sheet.FirstRowNum;                    }                    //最后一列的标号                    int rowCount = sheet.LastRowNum;                    for (int i = startRow; i <= rowCount; ++i)                    {                        IRow row = sheet.GetRow(i);                        if (row == null) continue; //没有数据的行默认是null　　　　　　　                                                DataRow dataRow = data.NewRow();                        for (int j = row.FirstCellNum; j < cellCount; ++j)                        {                            if (row.GetCell(j) != null) //同理，没有数据的单元格都默认是null                                dataRow[j] = row.GetCell(j).ToString();                        }                        data.Rows.Add(dataRow);                    }                }                return data;            }            catch (Exception ex)            {                Console.WriteLine("Exception: " + ex.Message);                return null;            }        }        public void Dispose()        {            Dispose(true);            GC.SuppressFinalize(this);        }        protected virtual void Dispose(bool disposing)        {            if (!this.disposed)            {                if (disposing)                {                    if (fs != null)                        fs.Close();                }                fs = null;                disposed = true;            }        }    }}

1.NPOI下载地址：http://npoi.codeplex.com/releases/view/38113

2.NPOI学习系列教程推荐：http://www.cnblogs.com/tonyqus/archive/2009/04/12/1434209.html

 

参考：

http://www.cnblogs.com/Erik_Xu/archive/2012/06/08/2541957.html

http://www.cnblogs.com/linzheng/archive/2010/12/20/1912137.html

http://www.cnblogs.com/knowledgesea/archive/2012/11/16/2772547.html