ExcelHelper ->NPOI插件

调用：

var ms = ExcelHelper.PrintInvoiceToExcel("观看时长", headline, items, (row, item) =>
            {
                row.CreateCell(0).SetCellValue(item.Id.ToString());
                row.CreateCell(1).SetCellValue(item.ActivityName);
                row.CreateCell(2).SetCellValue(item.MainVenue == 1 ? "主会场" : "分会场");
                //row.CreateCell(3).SetCellValue(item.Surname);
                row.CreateCell(3).SetCellValue(item.Name);
                row.CreateCell(4).SetCellValue(item.Mobile);
                row.CreateCell(5).SetCellValue(item.Email);
                //row.CreateCell(6).SetCellValue(sec_to_hms(item.Duration));
                row.CreateCell(6).SetCellValue(item.UserSumTime.ToString());
                row.CreateCell(7).SetCellValue(item.CTime.ToARCTimeString());
                row.CreateCell(8).SetCellValue(item.UTime.ToARCTimeString());
                row.CreateCell(9).SetCellValue(item.LivelodTime.ToString());
                row.CreateCell(10).SetCellValue(item.LiveWatchTime.ToString());
            });

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>
        /// 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);
                    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(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)
                        {
                            ICell cell = firstRow.GetCell(i);
                            if (cell != null)
                            {
                                string cellValue = cell.StringCellValue;
                                if (cellValue != null)
                                {
                                    DataColumn column = new DataColumn(cellValue);
                                    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;
            }
        }

        #region Excel

        #region 生成下载文档

        /// <summary>
        /// 生成下载饿 EXCEL文档
        /// </summary>
        /// <typeparam name="T"> </typeparam>
        /// <param name="sheetName"> sheet名称 </param>
        /// <param name="headline"> 标题列表 </param>
        /// <param name="list"> 数据集 </param>
        /// <param name="bindRowAction"> 绑定数据委托 </param>
        /// <returns> </returns>
        public static MemoryStream PrintInvoiceToExcel<T>(string sheetName, string[] headline, List<T> list, Action<IRow, T> bindRowAction)
         where T : new()
        {
            var listHead = new List<string>();
            listHead.AddRange(headline.ToList());
            //创建工作薄
            var wk = new HSSFWorkbook();

            //创建一个名称为mySheet的表
            var tb = wk.CreateSheet(sheetName);
            //创建一行，此行为第二行
            var head = tb.CreateRow(0);
            var heads = listHead.ToArray();
            for (var i = 0; i < heads.Length; i++)
            {
                var cell = head.CreateCell(i);
                cell.SetCellValue(heads[i]);
                cell.CellStyle = GetCellStyle(wk, "微软雅黑", HSSFColor.White.Index, 10, HSSFColor.BlueGrey.Index);
            }

            if (list.Count > 0)
            {
                var i = 1;
                foreach (var item in list)
                {
                    var row = tb.CreateRow(i);
                    bindRowAction.Invoke(row, item);
                    i++;
                }
            }
            try
            {
                var result = new MemoryStream();
                wk.Write(result);
                return result;
            }
            catch (Exception)
            {
                // ignored
            }

            return null;
        }

        /// <summary>
        /// 获取excel文件名字
        /// </summary>
        /// <param name="fileName"> </param>
        /// <returns> </returns>
        public static string GetFileName(string fileName = "")
        {
            fileName = string.IsNullOrWhiteSpace(fileName) ? DateTime.Now.Ticks.ToString() : fileName;
            return $"{fileName}-{DateTime.Now.ToARCBjTime().ToARCDateString()}.xls";
        }

        private static ICellStyle GetCellStyle(HSSFWorkbook wk, string fontfamily, short fontcolor, int fontsize, short bgColor)
        {
            ICellStyle cellstyle = wk.CreateCellStyle();
            cellstyle.SetFont(GetFontStyle(wk, fontfamily, fontcolor, fontsize));
            cellstyle.FillPattern = FillPattern.SolidForeground;
            cellstyle.FillForegroundColor = bgColor;
            cellstyle.VerticalAlignment = VerticalAlignment.Top;
            return cellstyle;
        }

        private static IFont GetFontStyle(HSSFWorkbook hssfworkbook, string fontfamily, short fontcolor, int fontsize)
        {
            IFont font1 = hssfworkbook.CreateFont();
            if (string.IsNullOrEmpty(fontfamily))
            {
                font1.FontName = fontfamily;
            }
            font1.Color = fontcolor;
            font1.IsItalic = false;
            font1.Boldweight = (short)FontBoldWeight.Bold;
            font1.FontHeightInPoints = (short)fontsize;
            return font1;
        }

        #endregion 生成下载文档

        #endregion Excel
    }