使用NPOI操作Excel(03、07)

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;
using NPOI.SS.Util;

namespace Common
{
    public 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>
        /// 生成Sheet对象
        /// </summary>
        /// <param name="fileName">导出Excel文件完整文件名</param>
        /// <param name="sheetName">要导入的excel的sheet的名称</param>
        /// <returns></returns>
        public ISheet GenerateSheet(string sheetName)
        {
            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();
            if (workbook != null)
            {
                sheet = workbook.CreateSheet(sheetName);
            }
            return sheet;
        }
        /// <summary>
        /// 将DataTable数据导入到excel中
        /// </summary>
        /// <param name="sheet">所要操作Excel的Sheet对象</param>
        /// <param name="data">要导入的数据</param>
        /// <param name="dataRowStart">数据起始行索引</param>
        /// <returns>导入数据行数(包含列名那一行)</returns>
        public int DataTableToExcel(ISheet sheet, DataTable data, int dataRowStart)
        {
            int i = 0;
            int j = 0;
            try
            {
                if (sheet != null)
                {
                    for (i = 0; i < data.Rows.Count; ++i)
                    {
                        IRow row = sheet.CreateRow(dataRowStart);
                        for (j = 0; j < data.Columns.Count; ++j)
                        {
                            row.CreateCell(j).SetCellValue(data.Rows[i][j].ToString());
                        }
                        ++dataRowStart;
                    }
                    workbook.Write(fs); //写入到excel
                }
                return dataRowStart;
            }
            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="dataRowStart">数据起始行索引</param>
        /// <returns>返回的DataTable</returns>
        public DataTable ExcelToDataTable(DataTable tableModel, string sheetName, int dataRowStart)
        {
            ISheet sheet = null;
            DataTable data = tableModel.Clone();
            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);
                    if (sheet == null) //如果没有找到指定的sheetName对应的sheet，则尝试获取第一个sheet
                    {
                        sheet = workbook.GetSheetAt(0);
                    }
                }
                else
                {
                    sheet = workbook.GetSheetAt(0);
                }
                if (sheet != null)
                {
                    IRow firstRow = sheet.GetRow(dataRowStart);
                    int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数
                    //最后一列的标号
                    int rowCount = sheet.LastRowNum;
                    for (int i = dataRowStart; 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;
            }
        }
        /// <summary>
        /// 设置表头（支持单元格合并）
        /// </summary>
        /// <param name="sheet">要合并单元格所在的sheet</param>
        /// <param name="mergeArrayList">需要进行单元格合并的单元格索引数组，数组长度为4，第一个为行起始位置，第二个为行结束为止，第三个为列起始位置，第四个为列结束为止</param>
        /// <param name="valueList">单元格合并后值的集合，与合并单元格索引数组集合一一对应</param>
        //public void SetCellRangeAddress(ISheet sheet, int rowstart, int rowend, int colstart, int colend, string value)
        public void SetExcelHeader(ISheet sheet, IList<int[]> mergeArrayList, IList<string> valueList)
        {
            for (int m = 0; m < mergeArrayList.Count; m++)
            {
                if (mergeArrayList[m].Length > 4)
                {
                    return;
                }
                int rowstart = mergeArrayList[m][0];
                int rowend = mergeArrayList[m][1];
                int colstart = mergeArrayList[m][2];
                int colend = mergeArrayList[m][3];
                string value = "";
                if (m < valueList.Count)
                {
                    value = valueList[m];
                }
                ICellStyle style = workbook.CreateCellStyle();
                style.Alignment = HorizontalAlignment.Center;
                IFont font = workbook.CreateFont();
                font.Boldweight = 700;
                font.FontHeight = 20 * 20;
                style.SetFont(font);
                for (int i = rowstart; i < rowend + 1; i++)
                {
                    IRow row = sheet.GetRow(i);
                    if (row==null)
                    {
                        row = sheet.CreateRow(i);
                    }
                    for (int j = colstart; j < colend + 1; j++)
                    {
                        ICell cell = row.CreateCell(j);
                        cell.SetCellValue(value);
                        cell.CellStyle = style;
                    }
                }
                if (rowend - rowstart > 0 || colend - colstart > 0)
                {
                    CellRangeAddress cellRangeAddress = new CellRangeAddress(rowstart, rowend, colstart, colend);
                    sheet.AddMergedRegion(cellRangeAddress);
                }
            }
            //workbook.Write(fs);
        }

        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;
            }
        }
    }
}