使用NPOI导出导入导出Excel

Excel2003

    #region Excel2003

    /// <summary>

    /// 将Excel文件中的数据读出到DataTable中(xls)

    /// </summary>

    /// <param name="file"></param>

    /// <returns></returns>

    public static DataTable ExcelToTableForXLS(string file)

    {

        DataTable dt = new DataTable();

        using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read))

        {

            XLS.HSSFWorkbook hssfworkbook = new XLS.HSSFWorkbook(fs);

            ISheet sheet = hssfworkbook.GetSheetAt();

            //表头

            IRow header = sheet.GetRow(sheet.FirstRowNum);

            List<int> columns = new List<int>();

            for (int i = ; i < header.LastCellNum; i++)

            {

                object obj = GetValueTypeForXLS(header.GetCell(i) as XLS.HSSFCell);

                if (obj == null || obj.ToString() == string.Empty)

                {

                    dt.Columns.Add(new DataColumn("Columns" + i.ToString()));

                    //continue;

                }

                else

                    dt.Columns.Add(new DataColumn(obj.ToString()));

                columns.Add(i);

            }

            //数据

            for (int i = sheet.FirstRowNum + ; i <= sheet.LastRowNum; i++)

            {

                DataRow dr = dt.NewRow();

                bool hasValue = false;

                foreach (int j in columns)

                {

                    dr[j] = GetValueTypeForXLS(sheet.GetRow(i).GetCell(j) as XLS.HSSFCell);

                    if (dr[j] != null && dr[j].ToString() != string.Empty)

                    {

                        hasValue = true;

                    }

                }

                if (hasValue)

                {

                    dt.Rows.Add(dr);

                }

            }

        }

        return dt;

    }

    /// <summary>

    /// 将DataTable数据导出到Excel文件中(xls)

    /// </summary>

    /// <param name="dt"></param>

    /// <param name="file"></param>

    public static void TableToExcelForXLS(DataTable dt, string file)

    {

        XLS.HSSFWorkbook hssfworkbook = new XLS.HSSFWorkbook();

        ISheet sheet = hssfworkbook.CreateSheet("Test");

        //表头

        IRow row = sheet.CreateRow();

        for (int i = ; i < dt.Columns.Count; i++)

        {

            ICell cell = row.CreateCell(i);

            cell.SetCellValue(dt.Columns[i].ColumnName);

        }

        //数据

        for (int i = ; i < dt.Rows.Count; i++)

        {

            IRow row1 = sheet.CreateRow(i + );

            for (int j = ; j < dt.Columns.Count; j++)

            {

                ICell cell = row1.CreateCell(j);

                cell.SetCellValue(dt.Rows[i][j].ToString());

            }

        }

        //转为字节数组

        MemoryStream stream = new MemoryStream();

        hssfworkbook.Write(stream);

        var buf = stream.ToArray();

        //保存为Excel文件

        using (FileStream fs = new FileStream(file, FileMode.Create, FileAccess.Write))

        {

            fs.Write(buf, , buf.Length);

            fs.Flush();

        }

    }

    /// <summary>

    /// 获取单元格类型(xls)

    /// </summary>

    /// <param name="cell"></param>

    /// <returns></returns>

    private static object GetValueTypeForXLS(XLS.HSSFCell cell)

    {

        if (cell == null)

            return null;

        switch (cell.CellType)

        {

            case CellType.BLANK: //BLANK:

                return null;

            case CellType.BOOLEAN: //BOOLEAN:

                return cell.BooleanCellValue;

            case CellType.NUMERIC: //NUMERIC:

                return cell.NumericCellValue;

            case CellType.STRING: //STRING:

                return cell.StringCellValue;

            case CellType.ERROR: //ERROR:

                return cell.ErrorCellValue;

            case CellType.FORMULA: //FORMULA:

            default:

                return "=" + cell.CellFormula;

        }

    }

    #endregion

Excel2007

    #region Excel2007

    /// <summary>

    /// 将Excel文件中的数据读出到DataTable中(xlsx)

    /// </summary>

    /// <param name="file"></param>

    /// <returns></returns>

    public static DataTable ExcelToTableForXLSX(string file)

    {

        DataTable dt = new DataTable();

        using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read))

        {

            XSSFWorkbook xssfworkbook = new XSSFWorkbook(fs);

            ISheet sheet = xssfworkbook.GetSheetAt();

            //表头

            IRow header = sheet.GetRow(sheet.FirstRowNum);

            List<int> columns = new List<int>();

            for (int i = ; i < header.LastCellNum; i++)

            {

                object obj = GetValueTypeForXLSX(header.GetCell(i) as XSSFCell);

                if (obj == null || obj.ToString() == string.Empty)

                {

                    dt.Columns.Add(new DataColumn("Columns" + i.ToString()));

                    //continue;

                }

                else

                    dt.Columns.Add(new DataColumn(obj.ToString()));

                columns.Add(i);

            }

            //数据

            for (int i = sheet.FirstRowNum + ; i <= sheet.LastRowNum; i++)

            {

                DataRow dr = dt.NewRow();

                bool hasValue = false;

                foreach (int j in columns)

                {

                    dr[j] = GetValueTypeForXLSX(sheet.GetRow(i).GetCell(j) as XSSFCell);

                    if (dr[j] != null && dr[j].ToString() != string.Empty)

                    {

                        hasValue = true;

                    }

                }

                if (hasValue)

                {

                    dt.Rows.Add(dr);

                }

            }

        }

        return dt;

    }

    /// <summary>

    /// 将DataTable数据导出到Excel文件中(xlsx)

    /// </summary>

    /// <param name="dt"></param>

    /// <param name="file"></param>

    public static void TableToExcelForXLSX(DataTable dt, string file)

    {

        XSSFWorkbook xssfworkbook = new XSSFWorkbook();

        ISheet sheet = xssfworkbook.CreateSheet("Test");

        //表头

        IRow row = sheet.CreateRow();

        for (int i = ; i < dt.Columns.Count; i++)

        {

            ICell cell = row.CreateCell(i);

            cell.SetCellValue(dt.Columns[i].ColumnName);

        }

        //数据

        for (int i = ; i < dt.Rows.Count; i++)

        {

            IRow row1 = sheet.CreateRow(i + );

            for (int j = ; j < dt.Columns.Count; j++)

            {

                ICell cell = row1.CreateCell(j);

                cell.SetCellValue(dt.Rows[i][j].ToString());

            }

        }

            /*不能使用如下方法生成Excel，因为在xssfworkbook.Write(stream);操作后会关闭流，导致报错【不能操作已关闭的流】*/

            ////转为字节数组

            //MemoryStream stream = new MemoryStream();

            //xssfworkbook.Write(stream);

            //var buf = stream.ToArray();

            ////保存为Excel文件

            //using (FileStream fs = new FileStream(file, FileMode.Create, FileAccess.Write))

            //{

            //    fs.Write(buf, 0, buf.Length);

            //    fs.Flush();

            //}

            /*可以使用下面方式导出*/

            MemoryStream stream = new MemoryStream();

            xssfworkbook.Write(stream);

            Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";//经过测试发现不添加会打不开excel本地可以

            Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}.xlsx", DateTime.Now.ToString("yyyyMMddHHmmssfff")));

            Response.BinaryWrite(stream.ToArray());

            xssfworkbook = null;

            stream.Close();

            stream.Dispose();

    }

    /// <summary>

    /// 获取单元格类型(xlsx)

    /// </summary>

    /// <param name="cell"></param>

    /// <returns></returns>

    private static object GetValueTypeForXLSX(XSSFCell cell)

    {

        if (cell == null)

            return null;

        switch (cell.CellType)

        {

            case CellType.BLANK: //BLANK:

                return null;

            case CellType.BOOLEAN: //BOOLEAN:

                return cell.BooleanCellValue;

            case CellType.NUMERIC: //NUMERIC:

                return cell.NumericCellValue;

            case CellType.STRING: //STRING:

                return cell.StringCellValue;

            case CellType.ERROR: //ERROR:

                return cell.ErrorCellValue;

            case CellType.FORMULA: //FORMULA:

            default:

                return "=" + cell.CellFormula;

        }

    }

注意：上文提到使用NPOI导出excel2007的时候会报错【不能操作已经关闭的流】，原因是在write的时候给Dispose了，故可以重写MemenryStream的Dispose接口，代码如下：

　　 /// <summary>

    /// 这是为了避免流被NPOI关闭而实现的流

    /// 当CanDispose为false时此流的dispose接口无效，仅当该值为true时有效

    /// </summary>

    public class ExcelStream:System.IO.MemoryStream

    {

        protected override void Dispose(bool disposing)

        {

            if (CanDispose)

            {

                base.Dispose(disposing);

            }

        }

        public bool CanDispose { get; set; }

    }

如下调用：

　　　　ExcelStream stream = new ExcelStream();

       workbook.Write(stream);

       stream.CanDispose = true;

注意：操作Excel2003与操作Excel2007使用的是不同的命名空间下的内容

使用NPOI.HSSF.UserModel空间下的HSSFWorkbook操作Excel2003

使用NPOI.XSSF.UserModel空间下的XSSFWorkbook操作Excel2007

感谢：http://blog.csdn.net/halym/article/details/9235823

感谢：http://www.cnblogs.com/yu-er/p/3434173.html

巴特西

使用NPOI导出导入导出Excel

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